Question

If a = 9 and c = 20, the measure of ∠B = ____ degrees (to the nearest tenth).

A) 24.2
B) 26.7
C) 63.3
D) 65.8
E) 68.2

Answer 1

63

Explanation:

cos(B) =

adj

hyp

cos(B) =

9

20

thus,

B = cos-1 (

9

20

)

B = 63.26

Answer 2

You are going to need to include a picture so we can see the triangle.