SOLUTION: Given a triangle with sides A = 10 m, and B = 4 m and C= 12 m, find the angle θ between sides A and B in degrees and radians.

Algebra ->  Trigonometry-basics -> SOLUTION: Given a triangle with sides A = 10 m, and B = 4 m and C= 12 m, find the angle θ between sides A and B in degrees and radians.      Log On


   

Question 1015013: Given a triangle with sides A = 10 m, and B = 4 m and C= 12 m, find the angle θ between sides A and B in degrees and radians.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use the law of cosines,
c%5E2=a%5E2%2Bb%5E2-2bccos%28C%29
12%5E2=10%5E2%2B4%5E2-2%2810%29%284%29cos%28C%29
144=116-80cos%28C%29
cos%28C%29=-28%2F80
C=110.5degrees
or
C=%28110.5%29%28%282pi%29%2F360%29=1.928rad