Answer:
d. 53.1°
Explanation:
The mnemonic SOH CAH TOA reminds you ...
Cos = Adjacent/Hypotenuse
You are given the lengths of t (hypotenuse) and r (adjacent to S), so you can find the angle from ...
cos(S) = r/t = 12/20
S = arccos(12/20) ≈ 53.1° . . . . . use the inverse cosine function