### Home > GC > Chapter 2 > Lesson 2.3.3 > Problem 2-121

2-121.

Use the relationships in the diagrams below to solve for , if possible. If it is not possible, state how you know. If it is possible, justify your solution by stating which geometric relationships you use.

The angles in a triangle sum to

.

So,.

How can you use the parallel lines to find an angle within the triangle?