Question 149987
If side a = 10, side b = 7, and side c = 8, find angle A.
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Use the Law of Cosines:
2bc*Cos(A) = b^2 + c^2 - a^2
Cos(A) = [49 + 64 - 100] / 2*7*8 = 0.11607...
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A = cos^-1(0.11607...) = 83.33.. degrees

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Cheers,
Stan H.