Question

Which lines, if any, must be parallel based on the given information? Justify your conclusion.

Answer 1

A must be parallel to b.

Proof:
∠3 = ∠13 (given)
∠15 = ∠13 (vertically opposite angles are equal)
Since ∠13 = ∠3 and ∠13 = ∠15, ∠15 = ∠3

Then, a must be parallel to b (transverse line d cuts parallel lines producing converse alternate angles that are equal (ie ∠15 = ∠3))

Answer 2

Answer:

Step-by-step explanation: