Question

21) Find the measure of angle B.

Answer 1

∠ B ≈ 56.3°

Explanation:

Using the cosine ratio in the right triangle

cos B =
`(adjacent)/(hypotenuse)` =
`(BC)/(AB)` =
`(5)/(9)` , then

B =
`cos^(-1)` (
`(5)/(9)` ) ≈ 56.3° ( to the nearest tenth of a degree )