Answer:
See below for answer.
Step-by-step explanation:
∠1 and ∠2 are supplementary Given
∠1 + ∠2 = 180° Definition of supplementary angles
∠3 and ∠2 are supplementary Given
∠3 + ∠2 = 180 Definition of supplementary angles
∠1 + ∠2 = ∠3 + ∠2 Substitution
∠1 = ∠3 Substracting ∠2 from both sides
