Answer:
66°
Step-by-step explanation:
Complementary angles are those that add up to 90 degrees. Since a and b are complementary, we can write:
∠a + ∠b = 90
We already know that ∠a = 24°, so we can plug this in:
24 + ∠b = 90
∠b = 90 - 24 = 66°
Thus, the answer is 66°.
