Answer:
46°
Explanation:
The mnemonic SOH CAH TOA reminds you ...
Cos = Adjacent/Hypotenuse
You are given the lengths of the hypotenuse of the triangle and the side adjacent to the angle you want to find. So, the cosine function describes the relationship:
cos(B) = AB/CB = (20 cm)/(29 cm)
B = arccos(20/29) ≈ 46.397°
B ≈ 46°