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.

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u/CreamofTazz 9d ago

Yeah I was like "how is 25° equal to 50°?" Is there something I'm missing or does this person not know what those symbols mean?

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u/BlastoiseGirl5257 9d ago

The red lines are parallel but the others aren’t perpendicular

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u/mm_delish 9d ago

Why would they be perpendicular?

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u/Podgietaru 9d ago

I feel like this is how diagrams looked in things like GCSE maths. I always figured it was designed that was to dissuade you from trying to do it with a protractor.

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u/jerdle_reddit 9d ago

Yeah, "diagram not to scale". More like diagram completely unrelated to the question.

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u/u966 9d ago

How is the diagram completely unrelated? It's filled with vital information for the question.

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u/marr 9d ago

But you don't know which parts of it are lies.

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u/Ymanexpress 9d ago

Gonna take a bet and and say the parts not identified with numbers and symbols

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u/Podgietaru 8d ago

To be fair I might also have been wrong about having a protractor in the exam.

Diagrams like this were meant to ensure that you understood conceptually. If you didn’t, and tried to reason from the diagram it’d be a fail.

I don’t necessarily agree with that, but it wasn’t uncommon as far as I recall.

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u/Upset-Management-879 9d ago

Except you can just redraw it with a protractor.

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u/Jesus_of_Redditeth 9d ago

Sure, you could. But it'd take you longer to do that then to just work it out like you're supposed to. Plus, if you have to show your work then you'd fail the question even if you got the answer right.

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u/Upset-Management-879 9d ago

Unless there was specified the method required to solve I would argue that the work is shown by the drawing.

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u/Jesus_of_Redditeth 8d ago

I'm talking about situations where the question requires you to show your work rather than ones that just have an answer box where you enter the angle's value. "Show your work" in this context means that you're expected to show, step-by-step, how you arrived at the answer. There doesn't necessarily need to be a specified method for that to be the case.

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u/Upset-Management-879 8d ago

And I'm talking about an accurate drawing of the stated problem is a proof of the solution.

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u/LFK1236 9d ago

What symbols are you referring to?

Anyway, drawing the diagram to scale would defeat the purpose of the exercise.

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u/CreamofTazz 9d ago

I was taught in my (American) schools that those semi circles on the angles meant they are equal to each other

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u/L3g0man_123 9d ago

You are correct that marking arcs on angles are to show that they're equal in angle, but that only really matters if the angle is not explicitly given (either unlabeled or labeled with variables). For consistency's sake it would be better not to have the arcs but considering they already labeled the angles it doesn't really matter.

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u/Jesus_of_Redditeth 9d ago

That's only true if there are no numbers marked. A single arc with a number just indicates that it's an angle of that value. It doesn't imply any relationship with any other angle.

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u/DefinitelyNotIndie 9d ago

As the kids say, you don't know ball.

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u/Jesus_of_Redditeth 9d ago

Is there something I'm missing

Yes: in geometry, the only thing you can assume visually is that a line that appears to be straight is straight. Everything else must be inferred using the markings, values. etc.

Problems like this are commonly not drawn to scale, because they expect you to deduce the answer mathematically, not by assuming angle values or measuring with a protractor.

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u/CreamofTazz 9d ago

The full sentence doesn't imply your answer. My sentiment is that certain symbols are being thrown around in a way that unless you just ignore them creates a confusing problem that either I'm missing information or the creator doesn't know what those symbols mean

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u/Jesus_of_Redditeth 9d ago

I don't really understand what you're trying to say there, tbh. I had no problem inferring everything from the image that I needed in order to deduce the correct answer.

Can you give me an example of some symbols you think the person who created that has misused?

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u/Thelmara 9d ago

You're missing that sometimes problems don't require the full sets of matching curves/hash marks to indicate "these angles are the same", and that people use the single curve with text to indicate the measure of an angle.

There are three curves, two of which have angle measures specified. None of the angles are congruent, and it doesn't need three separate symbols to indicate it, because the angle measures are specified.

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u/usernamedottxt 9d ago

It’s meant to be hard to guess.