Answer:
Explanation:
Reasons
2. If two lines are parallel, their corresponding angles are congruent.
3. Congruent angles are equal... Why do they even have this step?
4. A straight line forms a linear pair.
5. Angles in a linear pair are supplementary.
6. ∠1 is supplementary to ∠3. Reason: If an angle is congruent to an angle that is supplementary to a third angle, the first and third angles are congruent OR Transitive Property.