# A triangle has sides A, B, and C. Sides A and B are of lengths #8# and #9#, respectively, and the angle between A and B is #(5pi)/12 #. What is the length of side C?

##### 1 Answer

Dec 16, 2016

#### Explanation:

The Law of Cosines tells us that

where

using a calculator (or spreadsheet) should (if I haven't messed up) give the answer above.