Question

In ∆ABC, if the lengths of a, b, and c are 22.5 centimeters, 18 centimeters, and 13.6 centimeters, respectively, what are m B and m C to two decimal places?
A.m B = 89.68°, and m C = 37.19°
B.m B = 53.12°, and m C = 89.68°
C.m B = 89.68°, and m C = 53.13°
D.m B = 37.20°, and m C = 53.12°
E.m B = 53.13°, and m C = 37.19°
please help!

Answer 1

Any ideas?

Answer 2

First use the Cosine Rule to find m angle C

cos C = a^2 + b^2 - c^2
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2ab

Answer 3

Then use the Sine Rule to find m < B