Answer:
See below for answer.
Explanation:
∠BCD is a right angle Given
∠ACB ≅∠CAD Given
A is in the interior of ∠BCD Given
m ∠BCD =90° Definition of right angle
m ∠ACD + m ∠ACD = m ∠BCD Angle Addition Postulate
m ∠ACD + m ∠ACD = 90° Substitution
∠ACD is complementary to ∠ACD Definition of complementary
∠CAD is complementary to ∠ACD If two angles are congruent, then their
complements are congruent.