### Home > CC3 > Chapter 9 > Lesson 9.2.2 > Problem 9-79

9-79.

Calculate the value of

*x*. Homework Help ✎

An exterior angle of a triangle is equal to the sum of the two remote interior angles.

*x* = 46 + 90

Notice that the 77° angle corresponds to the angle adjacent to angle *x*. This angle is complementary to angle *x*.

The vertical angle is equal to the 77° angle because they are alternate interior angles on parallel lines.