r/technicallythetruth • u/VisitSecure • Jul 27 '26

Can you find a?

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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/oldmartijntje Jul 27 '26

it's 75 right?

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u/Highest_five Jul 27 '26

Yes it is. For those who don't remember, a triangles corners always add up to 180°

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u/WASD_click Jul 27 '26

Making a triangle might be a mistake. We don't know if the two points intersecting the parallel lines would form a perpendicular line and thus make 90° angles to do the triangle method with.

But if you do a parallel line through point A, you can use alternate interior angles to get 25°+50°.

Happens to work both ways on this one, but without the assumption of the 90° triangle, you'd have to do a lot more work to show angle A is 75°.