### Home > CCG > Chapter Ch7 > Lesson 7.2.3 > Problem 7-77

7-77.

* *is referred to as an **exterior angle** of * *because it lies outside the triangle and is formed by extending a side of the triangle.

If

and, what is? Show all work.How do the angles of a triangle relate to each other? How will this help you solve for

? Then how are and related? If

and, then what is?Use similar methods to those used for part (a). The methods might be used in a different order.