Answer:
Proved.
Step-by-step explanation:
Given: q is parallel to r
Statement: m∠1 = m∠2
Reason: Vertically Opposite Angles
Statement: m∠2+m∠3=180°
Reason: Same-side Interior Angles
Recall that m∠1 = m∠2
Statement: m∠1+m∠3=180°
Reason: Congruent Angles (m∠1 = m∠2)
Therefore, angle 1 is supplementary to angle 3.
Proved.