### Home > GC > Chapter 3 > Lesson 3.2.4 > Problem 3-82

3-82.

**Examine** the diagrams below. For each one, write and solve an equation to find . Show all work.

Equilateral triangles have three congruent angles.

Use the Pythagorean Theorem to solve for

.

Because

and are alternate interior angles, they are congruent. Therefore, .