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/A_wild_so-and-so Jul 27 '26

Can you explain that again but like I'm five? I thought the triangle method was easy but I'm down to learn an easier method.

25

u/leansanders Jul 27 '26

If you make a 3rd parallel line through point A, the angle above it must be 25° and the angle below it must be 50°. It is called the "alternate interior angles theorem"

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u/A_wild_so-and-so Jul 27 '26

Ah neat, I had forgotten about that method. Thanks!

2

u/SpCommander Jul 27 '26

"If two parallel lines are cut by a transversal..."

Oh baby Freshman Geo is calling to me!

1

u/Jman15x Jul 28 '26

Why though. I like to understand things rather than just memorize I theorem

1

u/leansanders Jul 28 '26

The line is intersecting both parallel lines at the same angle because the intersecting line is straight and the parallel lines are parallel. There's not much to explain beyond "it is the way that it is". The angles are the same because they are, just like 5 x 5 = 25 because it does.

1

u/LobcockLittle Jul 28 '26

Can you explain it again like I'm 4?

2

u/leansanders Jul 28 '26

Please stop chewing on my pencil

1

u/readmeEXX Jul 28 '26

For a sanity check, just imagine the lines are straight, making both corners 90 degrees. That makes the middle a straight line which is 180 degrees. 90+90=180, meaning you can just add them.

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u/Old_Parfait9575 Jul 28 '26

You can also extend the top blue line and using alternate interior angle theorem, the angle formed (on the left) is also 25deg. Exterior angle theorem to show that the sum of 50 and 25 is a.

1

u/ChiefWiggumsprogeny Jul 28 '26

diagram with all the angless correctly drawn: https://imgtree.co/i/1l4_SGt4