Question

I need help in this problem

Answer 1

b. 20°

Explanation:

Find the missing angle in the top triangle:

180 - 40 - 20 = 120

because, the sum of interior angles of a triangle is 180.

The top angle of the bottom triangle = 120 because it is a vertical angle to the one you just found.

Now find the missing angle (x) on the bottom:

x = 180 - 120 - 40 = 20