Question

which angle is complementary to ∠bdc?

Explanation:

Step1: Recall complementary angles sum to 90°

Complementary angles: sum = 90°

Step2: Identify angle at D with BDC

Assume right angle at D; BDC + adjacent angle = 90°

Step3: Determine adjacent angle

Adjacent angle to BDC forming right angle is ADB

Answer:

Angle ADB