In the proof below, what reason is missing? Given: ∠1 and ∠2 are right angles.

Prove: ∠1 ≅ ∠2

Statement Reason

1. ∠1 and ∠2 are right angles. 1. Given

2. m∠1 = 90° and m∠2 = 90° 2. Definition of a right angle.

3. m∠1 = m∠2 3. ?

4. ∠1 ≅ ∠2 4. Angles with the same measure are congruent.

A. Subtraction Property of Equality

B. Addition Property of Equality

C. Transitive Property of Equality

D. Angles with the same measure are congruent.