Question

A side of the triangle below has been extended to form an exterior angle of 129'. Findthe value of x. 20

Answer 1

Take into account that angles x and 129 are supplementary angles, that is, they add up 180 degrees.

Then, you can write:

x + 129 = 180

solve the previous equation by subtracting 129 both sides

x = 180 - 129

x = 51

Hence, the value of x is 51