### Home > CC3 > Chapter 9 > Lesson 9.1.1 > Problem 9-9

9-9.

If and

*, find the measures of each numbered angle. Then explain how you found each angle, citing definitions and conjectures that support your steps.*

Since two of the lines are parallel, their alternate interior angles and corresponding angles are equal to each other.

Angles 1, 2, and 3 form a straight angle, as do angles 4 and 5 and angles 6 and 7.