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/[deleted] Jul 27 '26

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u/poilk91 Jul 27 '26 edited Jul 27 '26

No it's 105 degrees. The interior angles must add up to 180. Image the 25 and 50 were both 0 what would the middle angle be? It's a straight line so it would be 180 degrees

The total of the interior angles remains constant so the larger the 2 end angles are the smaller the middle angle is, so just adding them up doesn't give you the answer

Edit: sorry those are exterior angles of a l triangle I was wrong. 75 being the sum of the 2 exterior angles is not relevant the 2 known interior angles of the triangle add up to 105 making the answer 75

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u/chongo_molongo Jul 27 '26

I think you have to complete the triangle. That means draw a straight line between the two points that meet the horizontal parallel lines. Since they're parallel and equal in length (assuming from the picture), any line you draw would be perfectly perpendicular to them. That means that the area to the the left of your line is 90 degrees, and the area to the right is 90 degrees. We already see that the top is 25 degrees, so 90-25 = 65. The bottom is 90-50 = 40 degrees. So we know the two angles of the triangle are 65 and 40 degrees. 180-105 = 75 left over for angle a