Question

M∥n, m∠1 = 50°, m∠2 = 48°, and line s bisects ∠ABC. What is m∠3?

Answer 1

49°

Explanation:

∠DEF = ∠1 +∠2 = 50° +48° = 98°

∠ABC = ∠DEF because they are alternate exterior angles, hence congruent.

∠3 = ∠4 because they are vertical angles.

∠3 = (1/2)∠ABC = (1/2)·98° . . . . . ∠4 is half of ∠ABC

∠3 = 49°