Question

In right triangle ABC, ∠A and ∠B are complementary angles, and sin A = 8/9. What is cos B?

a. 1/9
b. 1/8
c. 15/17
d. 17/15

Answer 1

In a right triangle with complementary angles ∠A and ∠B, sin A = cos B. Since sin A is given as 8/9, then cos B is also 8/9.

Step-by-step explanation:

The question is asking us to find the value of cos B in a right-angled triangle where ∠A and ∠B are complementary and sin A is given as 8/9. Since ∠A and ∠B are complementary in a right triangle, sin A = cos B. Therefore, if sin A = 8/9, then cos B is also 8/9. Without additional context, we assume that the given value of sin A is for the angle in standard position and referring to the principal value. Thus, the answer is sin A which is also equal to cos B, so the value of cos B is 8/9.