Answer:
30°
Step-by-step explanation:
The ratio of the side opposite (AB) to the hypotenuse (AC) is ...
4.5/9 = 1/2
From your memory of a short table of trig functions you know this is the sine of 30°. From the mnemonic SOH CAH TOA, you know that
Sin = Opposite/Hypotenuse
Putting these facts together gets you ...
sin(C) = 1/2 = sin(30°)
C = 30°
