Question

in the figure shown, which pair of angles must be complementary?
∠cob and∠aoc
∠cod and ∠dob
∠aoc and ∠dob
∠aoc and∠cod

Explanation:

Step1: Recall complementary - angles definition

Two angles are complementary if the sum of their measures is 90°.

Step2: Analyze the figure

From the figure, we can see that ∠AOC + ∠COB=180° (a straight - angle), ∠COD + ∠DOB = 90° (as indicated by the right - angle symbol at ∠COB).

Step3: Identify the complementary pair

Since the sum of ∠COD and ∠DOB is 90°, they are complementary.

Answer:

∠COD and ∠DOB