A triangle has sides A, B, and C. Sides A and B are of lengths 4 and 3, respectively, and the angle between A and B is (5pi)/12 . What is the length of side C?

1 Answer
Aug 9, 2016

C=4.34

Explanation:

As per law of cosines
C^2=A^2+B^2-2Atimes Btimescos(theta) where A=4;B=3 and theta=(5pi)/12
or
C^2=4^2+3^2-2times4times3timescos((5pi)/12)
or
C^2=16+9-24times0.2588
or
C^2=25-6.2
or
C^2=18.8
or
C=sqrt18.8
or
C=4.34