SOLUTION: 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

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Question 1027220: 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
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
The law of cosines solved for the cosine is

cos%28B%29=%28a%5E2%2Bc%5E2-b%5E2%29%2F%282ac%29

Substitute:

cos%28B%29=%2822.5%5E2%2B13.6%5E2-18%5E2%29%2F%282%2822.5%29%2813.6%29%29

cos%28B%29=0.6000163399

B=%2253.13%B0%22

The formula for C is

cos%28C%29=%28a%5E2%2Bb%5E2-c%5E2%29%2F%282ab%29

You do that one.

Edwin