Chapter 2 - Section 2.1 - The Parallel Postulate and Special Angles - Exercises - Page 87: 8

A) Angle 12 B) Angle 12

A) The two corresponding angles are the angles in the same position with respect to their own line when they are cut by the same transversal line, in this case line C. Thus, we see that angle 12 is the corresponding angle to angle 5. B) Alternate interior angles are angles cut by the same transversal, in this case line C, but which are in opposite positions. Thus, we see that angle 12 is the alternate interior angle.