SOLUTION: Use the Law of Cosines to fi nd angle C if side a= 20, side b= 25 and side c= 22

Algebra ->  Trigonometry-basics -> SOLUTION: Use the Law of Cosines to fi nd angle C if side a= 20, side b= 25 and side c= 22      Log On


   

Question 820009: Use the Law of Cosines to fi nd angle C if side a= 20, side b= 25 and side c= 22
Answer by ortarico(23) About Me  (Show Source):
You can put this solution on YOUR website!
You didn't state the range of titha but I'll leave my answer with the value for Acute.
a = 20
b = 25
c = 22
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Cos C = (a^2 b^2 - c^2/2ab
Cos C = (20^2 25^2 - 22^2)/2(20)(25)
Cos C = (400 625 - 484)/1000
Cos C = 541/1000
Cos C = 0.541
C = ARC(COS) 0.541
C = 57.25deg