The two-column proof below describes the statements and reasons for proving that corresponding angles are congruent: StepStatementsReasons

1segment UV is parallel to segment WZGiven

2Points S, Q, R, and T all lie on the same line. Given

3m∠SQT = 180°Definition of a Straight Angle

4m∠SQV + m∠VQT = m∠SQTAngle Addition Postulate

5m∠SQV + m∠VQT = 180°Substitution Property of Equality

6m∠VQT + m∠ZRS = 180°Same-Side Interior Angles Theorem

7 Substitution Property of Equality

8m∠SQV + m∠VQT − m∠VQT = m∠VQT + m∠ZRS − m∠VQT

m∠SQV = m∠ZRSSubtraction Property of Equality

∠SQV ≅ ∠ZRSDefinition of Congruency

What is the missing statement for step 7?

m∠SQV + m∠VQT = 180°

m∠VQT + m∠ZRS = 180°

∠SQV + m∠VQT = m∠VQT + m∠ZRS

m∠SQV + m∠SQT = 180°