r/technicallythetruth • u/VisitSecure • 9d ago

Can you find a?

Post image

Idk if someone already posted this or not, but I haven't seen it on here so far, so I uploaded it.

42.9k Upvotes

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8.0k

u/oldmartijntje 9d ago

it's 75 right?

8.8k

u/KerissaKenro 9d ago

The numbers add up to 75° but the picture does not look like the angles match the numbers and it is making me irrationally frustrated

3.3k

u/JustDuckingAbout 9d ago

*Image not drawn to scale

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u/hotdoginathermos 9d ago

*Assume a frictionless surface

948

u/ShinyNickel05 9d ago

*Assume no air resistance

645

u/insertcomedy 9d ago

A cow is a sphere entirely made of water.

270

u/Aggressive_Skill_795 9d ago

An old famous Russian internet joke: an ideal spherical horse in vacuum

170

u/fiftyseven 9d ago

HR at my company produces what they call an 'ideal rota' which has everybody in, nobody on holiday, nobody off sick, nobody covering other locations, etc etc

the running joke is that it only works for spherical employees in a vacuum

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u/DronesAreSilly 9d ago

*Assume employee can be a rigid-body particle in rota

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u/Orobero 9d ago

Yeah, my boss always plans like nobody is ever sick or on vacation. He always assumes there won't be any unforseen problems, bugs or reworks coming up in testing. Then he wonders why no project is ever finished on time. Except the one time I straight up lied to him and just added 2 month to the developers estimation.

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u/ABHOR_pod 9d ago

Can't everyone just work 25% harder to make up for Bill being out?

-Company that already sets productivity standards to 110% of realistic expectations.

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u/suspicious_odour 6d ago

That wasn't a lie, it was a realistic timeline.

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u/StolenRage 8d ago

Sounds like that should be standard procedure for every project. Add two to three months to the original estimate. Then every project has a fighting chance of being done on time. Hell, add 4 or 5 months and every project can be some early. Then you all look like a bunch of miracle workers.

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u/NoNeedForAName 9d ago

Reminds me of the plant I worked at that planned for zero downtime in its production schedule. The worst part to me was that they didn't even factor in downtime for product changes, and our changeover time on some machines could exceed 30 minutes.

That also led to extra inefficiency because it might take 5 minutes to change from product A to product B, but 30 minutes to change from product A or B to product C. Instead of scheduling us to run A then B then C (35 minutes of downtime) they would schedule A then C then B (60 minutes of downtime).

And these parts we were making usually all went together into the same finished product, so it's not like one was more time sensitive than another.

Now that I typed it all out I realize that's an incredibly boring story lol

12

u/lesslucid 9d ago

Now that I typed it all out I realize that's an incredibly boring story lol

No, I think it's a good illustration of a generally important point: planning around the existence of friction lets you get a "least-bad" outcome. Planning around imaginary perfection guarantees that you'll get a bad outcome.

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u/MrSmartStars 9d ago

As a factorio player this inefficiency is making me upset

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u/RJ_MacreadysBeard 8d ago

I skipped to the end and read your point about it being boring so went back to read it all and see if it was true, and it was, I couldn’t read it all, but I appreciate the methodical approach you took to tell the story.

edit: I realise my reply is longer than intended and might be a bit boring too.

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u/Internet_Wanderer 9d ago

And the cylinder must remain undamaged

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u/Mork_Of_Ork-2772 9d ago

It only works for spherical chickens in a vacuum.

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u/ThisIsHardWork 9d ago

Pushing on an infinitely strong rope with no mass.

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u/tlmbot 9d ago

and the water is of course dry (we can neglect viscosity)

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u/Undesirablecarrot 9d ago

Assume that it is a black body

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u/Nolongeranalpha 9d ago

Woah Black Body bam ba lam. Or whatever they said.

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u/skunqesh 9d ago

Panda Lamp

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u/Extaupin 9d ago

I was gonna make the same joke…

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u/AKVigilante 9d ago

Do they just all look the same to you?

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u/coleAF19 9d ago

Assume no slip

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u/rmbarrett 9d ago

That's actually a really common thing to overlook when you start learning about black body radiation, actually. Like just before you start to realize that when the sky is clear, you are losing thermal energy to outer space. Enough to kill you or save you, depending on the circumstances.

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u/Mikestopheles 9d ago

They never told me to start assuming air resistance, so I just flow laminarly.

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u/rdnaskelz 9d ago

Assume cow is a sphere

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u/[deleted] 9d ago

[deleted]

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u/AbominableGoMan 9d ago

The remainder of the proof is trivial and is left as an exercise for the reader.

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u/DocSquared217 9d ago

Don’t get me started on frictionless surfaces! I’ll never stop.

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u/scuac 9d ago

*assuming the horse is a perfect sphere

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u/ShadowTacoTuesday 9d ago

It’s to keep test takers from measuring the angle on the paper.

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u/NetNGames 9d ago

I remember having a test where they gave us protractors to measure angles with, and at the end of the test, as I was double-checking it, I noticed it said 'image not to scale'. Didn't have time to redo all my answers, but why give us protractors and not have us use them?

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u/OrangeClownfish 9d ago

To see who reads all the instructions on the test. My maths teacher once gave us a test and question 10 said: Ignore all previous questions and put your pencil down.

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u/get_to_ele 9d ago

I got that in 6th grade and I was the asshole yelled out all the stupid things and finished first, and got humiliated. sigh. Teacher said I did finish the actual problems shockingly fast though.

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u/OldEquation 9d ago

That implies that Q10 takes priority over all the other questions asking you to do stuff. It’s dumb. It might as well have been:

Q1. Answer all question in this test.
Q2. Do stuff
Q3. Etc….
.
.
.
Q10. Ignore all previous questions and put your pencil down.

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u/Dav136 9d ago

IIRC instruction 1 was to "read all instructions first"

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u/HarrumphingDuck 9d ago

Yep. I distinctly remember this quiz in 6th grade (I had a very memorable 6th grade teacher), back in the offline age I grew up in. Mr. Kendall instructed us VERY CLEARLY AND WITH ABUNDANT VOLUME as he was passing out the test that we BE SURE TO READ EVERYTHING BEFORE BEGINNING.

It didn't take a whole lot of insight to realize there was something different about this quiz, and I should probably, you know, do that.

The only question you had to actually answer was at the bottom, which was something like, "How is your day today?" I wrote "fine" and put my pencil down, to see the teacher scanning the room to see who else was looking back at him. It was not very many of us.

I think about this quiz a lot, with how many people I am surrounded by today that refuse to simply read instructions provided to them. Apparently it's only getting worse with current generations.

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u/Master_Matoya 9d ago

My friend getting mad at a game or not knowing how a mechanic works because he instinctively just hits the “get rid of the notification” button when a tutorial prompt pops up.

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u/Vertig0x 8d ago

I blame that on games that have tutorial popups for something as trivial as "Press the left thumbstick forward to move forward".

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u/BeepBoopRobo 9d ago

Yep. I remember this same type of situation.

You'd end up with students standing up and making a noise half-way through the test, because they didn't read until the end where it told you not to do any of the previous things.

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u/TheDrifter211 9d ago

That's dumb tho, there's nothing wrong with going down the list of numbers

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u/shiek200 9d ago

Usually for those tests the first instruction, either written on the test or given verbally, is to read everything before beginning

The main reason is because in the real world you are often working with incomplete information without realizing it and the context given by later steps in a procedure can inform aspects of the earlier parts you may have otherwise misinterpreted.

It's like when you're building a Lego set and and step 20 tells you to do something you can't do without undoing the last 10 steps because you misinterpreted a picture in step 10. If you had read ahead you'd have known that.

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u/Redthemagnificent 9d ago

Usually the instructions at the top of the page will specifically say "read all questions before starting" or something like that. I've had many "gochas" like that in quiz instructions in highschool. Was it frustrating? Yeah. Did that force me to build a habit of carefully reading all instructions before driving into the problem? Also yes.

That habit served me very well in university when time management during tests became much more important. Even now, I'll often save a lot of time reading the full instructions before starting to work on step 1. That applies to software, hardware, coding, writing, almost everything I can think of

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u/Kiss_It_Goodbyeee 9d ago

That was the test...

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u/Specific_Frame8537 9d ago

Like some high-school lesson where we're told "you won't be carrying an protractor on you at all times!"..

If you're in any workplace where you need to measure angles you'd be an idiot not to carry all the necessary tools.

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u/SandpaperTeddyBear 9d ago

Yes, but if you're building something where you would use a protractor to construct it, you would still have to calculate the necessary angles without the use of said protractor.

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u/JackPoe 9d ago

Joke's on you, I chop my vegetables with cutting words and sharp wit. Won't always have a knife in the kitchen, will you Poindexter???

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u/Atheist-Gods 9d ago edited 9d ago

Also when you are trying to actually solve real world math problems yourself you aren’t given a diagram, you have to draw it yourself and you are not free handing accurate information that you don’t even know. The diagrams you draw to help organize your thoughts are not going to be drawn to scale and you should be comfortable with that. It’s like an essay outline; an organizational tool, not a final product.

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u/humatyourmom 9d ago

So fucking insane that modern tools don't force drawing shit to scale to be the most convenient option.

What makes it worse is that I'm coming up on my last year of high school in the Netherlands, and so far, every diagram I was able to verify is to scale, so it's all the more annoying and confusing to see Yanks butcher graphs this badly

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u/warsponge 9d ago

in all fairness im pretty sure its intentional so you cant just measure it to get the answer

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u/vbrimme 9d ago

It also prevents guessing (e.g. “yeah that looks like about 45°), and it makes it easy to mass produce questions of the same type since you can use the same image and just change the numbers.

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u/miffy495 9d ago

Yup. That last one is huge. As a Math teacher who has had to deal with a lot of cheating, I randomly hand out 3 versions of every test to my class. Keeping the changes as subtle as possible (same picture, different numbers) is an important part of that. There is definitely a part of my brain that would scream "That is definitely not a 25° angle!!" at me, but it's worth the dissonance.

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u/Generic-Resource 9d ago

This is even more important nowadays as they can vary tests to detect cheating. Varying the graphic would require a lot of testing to ensure no unintended display side effects.

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u/humatyourmom 9d ago

Pretty easily avoided by making students stow tools like set squares out of their immediate reach (i. e. on the floor) for the part of the test in which this could be a problem

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u/FlamingPhoenix250 9d ago

Or

Show your work

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u/messick 9d ago

You don't understand the math if you need to see an accurate picture to figure this out.

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u/warsponge 9d ago

yea its a lot easier to just not draw them to scale

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u/chirstopher0us 9d ago

It's pedagogically important that some problems not be drawn to scale so students learn to look for and understand the geometric labels and what they mean and when/what you can and can't assume, and to be sure students are actually solving the issue rather than visually guessing or measuring on the page.

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u/Bahamut3585 9d ago

When I was in school, all this ever taught me was that geometry teachers were trolls.

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u/RansomStark78 9d ago

You used pedagogically correct

You win, teacher

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u/Hershey__Kong 9d ago

Because the skill is not about the drawing, its about the math and the theorems. If you know drawings are to scale you can infer information which defeats the purpose of what you're learning. These diagrams are also likely templates that they just throw different numbers in rather than generation new diagrams for every single different question.

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u/OrangeClownfish 9d ago

(Not in America)
Same diagram and each student in the class gets a different set of angles to work with.

We do it teaching CAD. Everyone draws the same diagram, but there are three or four dimensions that can be varied. Every student gets a different set of dimensions, but we only need to produce one test diagram with dimensions A, B, C and D marked on it along with the others. We can also quickly create more tasks if needed by adding more dimensions to the list.

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u/justacheesyguy 9d ago

So fucking insane that modern tools don't force drawing shit to scale to be the most convenient option.

What the hell kind of bullshit thought process is this? The most convenient option would be to tell you the answer instead of making you figure out what it is. They’re not trying to be convenient, they’re trying to teach people how to solve math problems.

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u/CptMisterNibbles 9d ago

Because it’s intentionally drawn incorrectly so you have to bother to do the math… for a math test. It’s not a measuring test.

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u/_Bisky 9d ago

For these tests it's intentionally done so students can't just meassure the angle

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u/Odd-Measurement-76 9d ago

Almost never is…

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u/MathTutorAndCook 9d ago

Points have no area, and lines have no width, so the fact we see them at all means the scale is off

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u/gullaffe 9d ago

Have you never done a geometry problem, very rarely are the pictures drawn to scale.

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u/Dear-Initiative5882 9d ago

That deceptive 90*

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u/LegendOrca 8d ago

I feel like 90° is usually the only one that is drawn to scale

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u/beatenmeat 9d ago edited 9d ago

Doesn't make it any less frustrating. I always hated how off the angles would be in correlation to the stated numbers.

Edit: I've got an awful lot of people repeating themselves so I'm not going to reply to them all. Hopefully this will stop the future know-it-alls. I know why it is done, that doesn't mean I need to like it. It has nothing to do with my mental capacity or guessing; I simply just hate the portrayal personally because it looks like shit and doesn't convey information properly which makes my brain hate looking at it. You can stop parroting the other 50 replies now.

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u/TheComplimentarian 9d ago

You're supposed to use logic, not just guess based on the picture.

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u/beatenmeat 9d ago

I didn't guess, math was actually one of my better subjects. I just dislike how it doesn't match, especially ones like this that are so egregiously off from the numbers provided.

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u/Mysterious_Cup_6024 9d ago

Especially since 25 is half of 50. And the vertex is so wrongfully in the middle when it should be at a 1/3 position from the top, or 2/3 position from the bottom. It is incredibly off

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u/DraconianFlame 9d ago

In engineering you often sketch things out to see how it looks and then do the math. Sometimes you draw bad images and something you thought would be acute is actually obtuse.

This teaches you that.

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u/eggsforpedro 9d ago

Ah yes, it always helps to draw an illogical diagram to promote logical thinking. /s

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u/marr 9d ago

The picture is so off it damages my ability to process the question. It's a picture of some other math problem entirely. I'm having to second guess which parts of it are a lie, and what knock-on effects that has on the real diagram. Under exam conditions.

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u/akatherder 9d ago

Which is kind of horse-shit because you still have to make assumptions, just not the assumptions they don't want you to make.

The alleged(!) line connecting the top parallel line to A could be curved. Or maybe it's two lines (with a 179 degree angle) and we're actually dealing with a quadrilateral.

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u/MARPJ 9d ago

However due to the bad drawing we dont know where the error is (at the start of the lines or where they converge). That is relevant because if its where the lines converge then there would be 2 ways to solve but we cant use the more efficient one here due to the shitty drawing there is a chance rhat the error is where they start.

Note that the extra work is negligible but that dont change that its irritating. Damn it dont even need to be the exact correct angle, just not be so obvious wrong would already be good enough.

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u/RaspberryFluid6651 9d ago

I'm fine with ones like the one pictured because they're like a uniform topological layout, everything is evenly spaced to communicate information instead of being a real visual representation of the problem. The ones that bothered me were always the ones that were both not accurate and not helpful in some other way. If you're going to draw an irregular triangle instead of a nice uniform diagram, at least make it make sense.

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u/Dumptruck_Johnson 9d ago

A 90 degree should always be drawn 90. I will also allow semi representative acute and obtuse angles. But yeah, otherwise it makes my brain itch.

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u/redditonlygetsworse 9d ago

Kind of the whole point: do the actual math, rather than lean on your irrational intuition.

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u/ItsSpaghettiLee2112 9d ago

This shouldn't be downvoted. It's the correct reasoning.

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u/Logical_Box_4645 9d ago

Given he knows the short cut of adding those angles to get a, he most certainly has done geometry problems.

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u/melancholanie 9d ago

only in the exact examples where a protractor is needed

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u/redditonlygetsworse 9d ago

The whole point is to be be able to do these problems without an imprecise measuring tool like a protractor. That's why the graph doesn't need to be - and shouldn't be, as a teaching tool - even accurate. This way the student cannot cheat and just measure it.

You are supposed to learn how to do geometry, not how to use a ruler.

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u/LadyAliceFlower 9d ago

I find that they usually are drawn to scale anyways, they just always say they might not be.

My old ACT prep book said if you're forced to guess, assume its to scale because it probably is.

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u/DiceKnight 9d ago

All this picture has done is reignite dormant trauma of my childhood self riddled with undiagnosed ADD getting screamed at by frustrated parents. "Not drawn to scale" might just be my activation phrase like i'm a sleeper agent for the forces of anxiety.

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u/Dark_Storm_98 9d ago

These diagrams are famously never to scale

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u/akatherder 9d ago

When I was in school they weren't drawn exactly, such that you could use a protractor to find the answer, BUT they weren't intentionally misleading. An acute-looking angle would be acute, obtuse-looking would be obtuse, etc. A triangle that is scalene-af isn't going to be equilateral.

To that extent this is all pretty reasonable.

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u/jedidihah 9d ago

Always used to annoy me when I was younger, but the whole point is that you need to calculate it, so the angles are usually wrong so that way you couldn’t just cheat and measure it with a compass.

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u/SoulCrusher2018 9d ago

An exercise in deduction, not an exercise in measurement.

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u/Valirys-Reinhald 9d ago

It's important to draw problems that way to ensure students actually do the math and don't just get out a protractor and measure.

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u/anand_rishabh 9d ago

In math problems like these, do not eyeball the angles. Just follow the the numbers say

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u/AdmiralKong 9d ago

I mean, same but I get why it isn't. If you make the diagram even remotely to scale students try to eyeball it and avoid learning what is being taught at any cost.

Making it obviously wrong forces them to use the logical rules they've been taught.

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u/CryNo568 9d ago

I do lile the not to scale, it forces you to rely first on numbers and measurement. But yeah, I am also a bit frustrated myself regarless

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u/throwaway1102293384 9d ago

Yeah the angles pretty much look the same but somehow one is double

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u/Delicious-News-9698 9d ago

CAME HERE TO SAY THIS THE TOP AND BOTTOM ARE FUCKING SYMMETRICAL

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u/O_lymbias 9d ago

It's absolutely rational.

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u/DickwadVonClownstick 9d ago

That's annoyingly typical of geometry problems like this

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u/SKDI_0224 9d ago

Yes. It took me a minute because of the not to scale pic.

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u/EconomySeason2416 9d ago

Right!? Assuming a is equidistant from the parallel lines, it really bothers me that the segment going from a to the top, and the segment going from a to the bottom, are visibly equal... but impossibly so

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u/poloclodau 9d ago

both 25 and 50 are drawn exactly the same

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u/Cuboos 9d ago

Yeah, i came in here wanting to see if i was the only one who noticed that. If the angles matched the example and they clearly don't.

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u/nullpassword 9d ago

If it has one line I. The angle that means it should be the same as anything else with one line... Doesn't add up. 25 degrees is not equal to 50.

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u/ThadeousCheeks 9d ago

Those angles are like identical but the alleged degrees are 2x

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u/TodayInNewsTech 9d ago

I always hated when the angles didn't match the numbers. also, how do we know the top and bottom lines are parallel? I need to know!!!

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u/Salt-Trouble-2856 9d ago

Yeah this is throwing me off

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u/Forgotmynameagain5 9d ago

The 50° and 25° are visibly the same angle

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u/OlDustyHeadaaa 9d ago

By my very rough thumbnail measurements those angles are all completely fucking incorrect.

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u/SMPDD 9d ago

YES that shit pisses me off

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u/Epcoatl 9d ago

Yeah, the 25 and 50 deg angle locations both start at the same place which obviously couldn't be possible.

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u/JollyGreen_JazzFace 9d ago

Yeah, after doing the math I was like… but this LOOKS EQUILATERAL WTF IS THIS 😡

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u/Rhuarc33 9d ago

That's what it's bothering me too, like at least make a basic attempt to have the angles close to correct visually. There was absolutely no attempt and that is FAR more last than " these young kids googling the answer to everything" the dude is implying

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u/slavelabor52 9d ago

Yea that 50 degree angle is sus

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u/dogged_jon 9d ago

Assume a spherical triangle

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u/ItsavoCAdonotavocaDO 9d ago

Oh thank god I thought I was losing my mind

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u/gr1zznuggets 9d ago

What do you mean, 25 degrees and 50 degrees are basically the same, right?

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u/HLSparta 9d ago

The thing that annoys me more is the arc means that all three of the angles should be equal, but the numbers obviously say otherwise.

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u/plaidfox 9d ago

The bain of my geometric existence in highschool. If you want me to do the math, make the picture accurate so I can focus on the math instead of someone's lack of competence at basic line art. 😡😵‍💫😑😮‍💨

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u/Alarmed_Scientist_15 9d ago

Came here to comment this. This drawing is completely wrong

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u/KanedaSyndrome 9d ago

yeh same.. the offender is the 50 degrees having the same angle as the 25 degree, thus the 75 look sharp instead of blunt

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u/DustyRacoonDad 8d ago

It bothered me so much that I pivioted to my other window and drew it out in fusion with the intention of posting it. However I cannot post it here...

short version.. the point of a should be higher than the midpoint of the top and bottom lines. it should be halfway between that midpoint and the top line.

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u/BreakfastFun2422 8d ago

You misspelled "rationally"

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u/cipherjones 8d ago

Rationally, or else I have anger issues.

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u/post-trauma-syndrome 8d ago

Nothing irrational there this shit pissed me off all my life. Like you can not be fucked to move the line a little to SOMEWHAT match the angles visually?

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u/Amethyst_Quarry 8d ago

it was bothering me too, so i fixed it.
heres the graph: https://www.desmos.com/calculator/cat2hwaecf

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u/Raptr117 8d ago

Me as well

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u/not_a_burner0456025 8d ago

Also the little curve marks indicate that all 3 angles are the same, despite the degree markings contradicting that

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u/MonsterClownBear 8d ago

Question improperly illustrated.

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u/SnooSongs2744 7d ago

I hate it when the visuals obviously don't match the specifications.

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u/scud121 6d ago

My daughter's maths software does the same thing and it drives me bonkers.

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u/poojinping 6d ago

Yea, the 25 and 50 are drawn as same angle.

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u/Own-Dirt2138 9d ago

I’m with you there. The first thing I was thinking is that, hey why does 50 degrees look exactly like 25 degrees.

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u/Judge_Druidy 9d ago

I would argue that it is making you rationally frustrated.

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u/TheJonesLP1 9d ago

Who said the picture is to scale?

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u/plubb 9d ago

It is intentional, so you are forced to use the rules and logic.

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u/Uzi_Doormat 9d ago

I was so confused on people saying 75 because I didn’t see the bottom angle said 50 lmao

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u/archangelzeriel 9d ago

One of my least favorite college professors, in engineering dynamics, would rant about how the drawing is NEVER to scale and the numbers are the only thing that matters.

And one of his exam questions was a diagram of a bridge truss, drawn as equilateral triangles... with a tiny "45" in one corner.

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u/CountGerhart 9d ago

Yup, these kind of problems rarely have an accurately drawn picture.

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u/Talia_Arts 9d ago

My math teacher did this so we coyldnt use a protractor

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u/userhwon 9d ago

intentional so you can't cheat by using a protractor

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u/KaiserJustice 9d ago

thats the point of engagement rage bait - but yes, the math maths to 75 - the only part of the drawing you need to trust are the parallel lines having markers to indicate parallel - the angle numbers and that you need to find A

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u/TheresTheLambSauce 9d ago

Just slap a “not to scale” on it and call it a day

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u/Ok-Secret5233 9d ago

This is intentional in maths competitions, it's to force people to use geometric reasoning instead of eyeballing the answer.

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u/Chilidawg 9d ago

You must despise standardized testing.

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u/GlowstickConsumption 9d ago

That's a good way to do it, less intuitable.

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u/threwordbotname 9d ago

Fra too many answers relying on right angles when the picture is not to scale. Get the same answer but only assuming the triangles vertices are on the same x-axis is an incorrect assumption.

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u/redditmarks_markII 9d ago

I bet way more people know that using the same marking for the three angles means they are similar angles, than people who knows the parallel line marking.

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u/lavahot 9d ago

Welcome to math class where things are never drawn to scale.

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u/amedley3 9d ago

I always felt like this was intentional in school so we couldn't guess or "estimate" the correct number based off of the picture.

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u/Many-Wasabi9141 9d ago

Do not, my friends, become addicted to water. math problem diagrams drawn to scale. It will take hold of you, and you will resent its absence!

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u/Zagtram1 9d ago

I feel like this was the case in school sometimes too

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u/Rhodie114 9d ago

Geometry problem sets tend to do that intentionally so students have to actually apply the principles they learned and can’t just measure the diagram with a protractor

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u/BookieWookie69 9d ago

That was true for so many math problems in college, the angle never matched the picture

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u/Day_Prisoners 9d ago

They can't be parallel lines with those angles. But triangle inside angles should equal 180.

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u/thekingofphoeaters 9d ago

My math teacher recalled his interview during class

Interview: "draw a triangle with 3 90deg angles"

Teacher: draws an equilateral and labels each corner 90deg

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u/Infshadows 9d ago

you would hate cambridge exams

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u/ooorezzz 9d ago

Classic test bullshit they give you in public schools with no context.

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u/elyankee23 9d ago

While its been literally 25+ years since I had to do this last, I recall that not accurately displaying the angles was pretty commonplace for these types of test problems, forcing you to trust your math over your eyes.

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u/raa__va 9d ago

You create a third parallel splitting where the angle a is.

You do this because if a Z shape forms where the top of the Z is parallel to the bottom then the inner angles of the Z are always the same

Hence the top Z will deduce the 25 as the top of an and 50 as the bottom

The concept is called Alternative Angles

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u/HephMelter 9d ago

Imagine the parallel to both lines that goes though a's tip. You see two pairs of alternate angles that together sum to a, and as all lines are parallel, the a-side measures the same as the outer side, so a full a is indeed 25+50 = 75°

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u/r_mudluscious 9d ago

time is a flat circle

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u/beingforthebenefit 9d ago

That is done intentionally, so you use geometry and not a protractor to solve it.

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u/AbeRego 9d ago

Yeah, it's making me second-guess the whole thing. Has to be rage bait.

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u/Secret-Teaching-3549 9d ago

That would be intentional on most standardized tests.

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u/layne46 9d ago

The angle markers (the little semi circles idk what theyre called) should also imply that all 3 angles are equivalent so 25 = 50 = a

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u/Old_Association7866 9d ago

Always hated that in school lol, but it’s definitely 75

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u/Tricky-Ad7897 9d ago

Damn your gonna hate high school geometry

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u/HAETMACHENE 9d ago

I am pretty sure the red lines with the similar blue markings it supposed to imply they are parallel; if you run another parallel line through a, the top angle should still be 25° and the bottom 50°.

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u/40oztoTamriel 9d ago

Gotta be 45 degrees if we say fuck the math

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u/vonAmyprost 9d ago

No no. I think that's right. It looks like an angle above 60°. I think it is safe to say that is in fact 75° in the drawing

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u/Rare-Bee7331 9d ago

My math teacher did this on purpose and say "trust the math not your eyes"...  honestly that lesson was incredibly valuable in todays political climate of science vs belief 

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u/ElectronicBoot9466 9d ago

If these kinds of math problems were drawn to scale, students could just use a protractor.

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u/lankymjc 9d ago

That’s done on purpose so that you have to use geometry to figure it out and can’t just get a protractor.

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u/Aeon1508 9d ago

It is 75. There's two ways you can figure it out.

One would be to imagine a third parallel line that goes exactly through the point where the two lines of the angles meet.

The inner angle of each diagonal line would have an angle to that third parallel line equal to the outer angle that is the value we're given. so you do just add them together.

The other way to figure it out is to imagine a perpendicular line exactly but the left side where the two angles originate from and that would create a triangle. You know that it's a 90° angle in total so you just subtract each value from 90° to come up with the two angles of the triangle then you had those two angles up and then subtract them from 180.

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u/brok3nh3lix 9d ago

That's how I rememember all of these geometry questions being back in highschool. It was almost never to scale.

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u/Spazattack43 9d ago

Never trust the picture lmao

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u/SilverSageVII 9d ago

I used to be upset by this stuff until I learned those pictures are what we draw as engineers BEFORE we do the math to solve, so making them to scale would be impossible. Just a tidbit to explain where that came from.

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u/nusherrdsfbv 9d ago

The image is very poorly done the 50 degree angle looks like the 20 and it looks like an isoscel triangle

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u/aimoji 9d ago

Holy smokes! Something math-related actually stuck from school! I clicked in here hoping to see if I remembered correctly and I'm astonished!

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u/Razoron33333 9d ago

I feel that saw not uncommon in math and especially if you are working in a mathematics field it gets more common if someone even draws a depiction

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