Answer:
Proved below.
Explanation:
Parallel lines and angles:
Given: p // q and ∠1≅ ∠2
Proof:
p //q, l is transversal,
∠3 ≅ ∠1 -----(I) {Corresponding angles are congruent}
∠1 ≅ ∠2 ---------(II) {Given}
From (II) & (I),
∠3 ≅ ∠2
∠3 and ∠2 are alternate interior angles. Alternate interior angles are congruent only if the lines are parallel.
⇒ l // m