Answer:
Step-by-step explanation:
1. ∠1 ≅∠3 1.Given
2. m∠1 = m∠3 1. Given
3. ∠1 and ∠2 are linear pair 3.) linear pair
4. ∠1 an ∠2 are supplementary 4. Definition of linear pair
5. ∠1 + ∠2 = 180 5. Definition of linear pair
6. ∠3 + ∠2 = 180 6.substitution property of equality
7. ∠2 an ∠3 are supplementary 7. Proven
