Chapter 3 - Parallel and Perpendicular Lines - 3-2 Properties of Parallel Lines - Practice and Problem-Solving Exercises - Page 153: 10

a) same-side interior angles theorem b) same-side interior angles theorem c) congruent supplements theorem

a) $\angle 3$ and $\angle2$ are same-side interior angles b)$\angle 1$ and $\angle2$ same-side interior angles c) Since $\angle 1$ and $\angle3$ have the same supplement, they are congruent.