Question

I need help with this geometry question asap!

Answer 1

Answer:

  (a)  Theorem 9

Step-by-step explanation:

Any of the given theorems can be used to prove lines are parallel. We need to find the one that is applicable to the given geometry.

Analysis

The marked angles are between the parallel lines (interior) and on opposite sides of the transversal (alternate).

Theorem 9 applies to congruent alternate interior angles.