Answer:
C ≈ 15.36
Step-by-step explanation:
The mnemonic SOH CAH TOA reminds you of the relationship between the adjacent side (C) and the hypotenuse (21):
Cos = Adjacent/Hypotenuse
Multiplying by the hypotenuse, we have ...
(Hypotenuse)·Cos = Adjacent
21·cos(43°) = C ≈ 15.36
