Question #6593b

1 Answer
Parabola
Dec 7, 2017

I will explain it at the "Explanation" section.

Explanation:

Let us have two intersecting lines with angles 1,2,3,4. Look at the picture for help.

enter image source here
We know that m/_1+m/_2=180, since they add up to a strait line.

Similarly, we also know that m/_2+m/_3=180.

We replace 180 with m/_2+m/_3 for the first equation to get:
m/_1+m/_2=m/_2+m/_3 Simplify the equation to get:
m/_1=m/_3

Therefore, vertical angles are always congruent.

Related questions
See all questions in Transformations and Congruence
Impact of this question
2509 views around the world
You can reuse this answer
Creative Commons License