Sample Response: Because vertical angles are congruent, angles 1 and 4 are congruent. Because corresponding angles are congruent, angles 4 and 8 are congruent. Because angle 4 is congruent to both 1 and 8, angle 1 is congruent to angle 8.
Answer: You can prove that and are congruent using the same method. The converse of this theorem is also true; that is, if two lines and are cut by a transversal so that the alternate exterior angles are congruent.
