Question

Anybody good with proofs?

Answer 1

I can help

Answer 2

This is my question, I figured out my last one out. Im just trying to figure it out before I fall asleep :D

Answer 3

An indirect proof is also known as a proof by contradiction. So, you have to prove that the sum of the angles is 180 by showing that it isn't any other value.

I'd start by saying that AB is a line segment. So, since it is a line segment, if angle 1 + angle 2 adds to anything but 180 degrees, then AB would not be a line segment. Therefore, since AB is a line segment, the angles must add up to 180 degrees.