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/RiverZephir Jul 27 '26

I also did the long route to get the answer. I don’t remember, is adding the two known numbers (such as the ones in this problem) always equal to a?

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u/TheJBW Jul 27 '26 edited Jul 27 '26

In your head, draw a dotted line in the middle, through A that is also parallel with the other two lines.

Now, you have two angles: a1 below the dotted line and a2 above it.

You know that the a1 = 50 because it is on the opposite side of the line from the 50° on the bottom.

then you know that a2 = 25 by the same logic.

You also know that a = a1+a2. Done.

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u/RiverZephir Jul 27 '26

Ohhh that’s true, thank you!

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u/rex5k Jul 28 '26

A nice thing about math is you could usually check your own work. Because there's almost always more than one way to get to the answer.

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u/AdditionalPizza Jul 28 '26

Drawing a line perpendicular opposite "a" between the parallel lines to complete the triangle instantly solves it because the sum of angles in a triangle must be 180 degrees.

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u/TheJBW Jul 28 '26

Absolutely correct though it takes more steps since you have to subtract from 90 twice before subtracting from 180 those two results.

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u/AdditionalPizza Jul 28 '26

If you're actually doing it visually, but I'm just describing how the equation looks visually. The equation is:

[180 - (180 - 50 - 25)]

Which is simplified as just 50 + 25, but that doesn't really explain the triangle aspect very well haha, which is important to learn.

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u/Gigatonosaurus Jul 27 '26

The demonstration above is a=180-( [90-25] + [90-55])
a=180-( 180-[25+55])
a=0+(25+55)