A triangle has sides A, B, and C. Sides A and B are of lengths #6# and #1#, respectively, and the angle between A and B is #(7pi)/8 #. What is the length of side C?
1 Answer
Feb 8, 2016
Explanation:
You can use the law of cosines here.
Let the angle opposite to side
Then the law of cosines states:
#C^2 = A^2 + B^2 - 2ABcos(gamma)#
# = 6^2 + 1^2 - 2*6*1cos((7pi)/8)#
# = 37 - 12cos((7pi)/8)#
# ~~ 37 - 12 * (-0.92)#
# ~~ 48.09 " units"^2#
Thus,
#C ~~ 6.93 " units"#
