Question

What is the value of

Answer 1

All angles in a triangle add up to 180 degrees.
We are finding the value for both y's (they are congruent) so I'll just plug in the answers to the problem.
Let's start with 54.
54*2=108
108+72=180
The answer is then A, 54 degrees

Answer 2

All values of angles in a triangle is equal to a total of 180 degrees.

We know that one angle is 72 degrees so we subtract that from 180 to get 108

180 - 72 = 108

We have two missing angles, both equal to y, so we divide the difference of 108 by 2 to get 54 degrees.
108/2 = 54 degrees

72 + 54 + 54 = 180
180 = 180


y = 54 degrees