Question

If b = 9 and c = 13, what is the measure of ∠A? (round to the nearest tenth of a degree)

A) 34.7°

B) 41.2°

C) 46.2°

D) 49.5°

E) 55.3°

Answer 1

The answer to this question is C

Answer 2

C) 46.2°

Explanation:

cos theta = adjacent side/ hypotenuse

cos A = b/c

cos A = 9/13

Taking the inverse cosine of each side

cos^-1 (cosA) = cos^-1 (9/13)

A = 46.18693854

A = 46.2 degrees