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!

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!

zale101 · Answer

Any ideas?

welshfella · Answer

First use the Cosine Rule to find m angle C

cos C  = a^2 + b^2 - c^2
             --------------
                       2ab

welshfella · Answer

Then use the Sine Rule to find m < B