Prove: Statement Reason
1. ∠GAC ≅ ∠AFD given
2. ∠GAC ≅ ∠AFE For parallel lines cut by a transversal, corresponding angles are congruent.
3.
4. ∠AFD and ∠AFE are supplementary. Linear Pair Theorem
5. m∠AFD = m∠AFE = 90° If two congruent angles are supplementary, then each angle is a right angle.
6. definition of perpendicular lines

What is the missing step in the proof?

A.
Statement: ∠GAC and ∠GAB are supplementary.

Reason: Linear Pair Theorem

B.
Statement: ∠AFE ≅ ∠AFD

Reason: Transitive Property of Equality

C.
Statement: ∠GAC ≅ ∠BAF

Reason: Vertical Angles Theorem

D.
Statement: ∠GAC and ∠AFD are supplementary.