# How do you solve a triangle if you are given a = 11, b = 14, c = 20?

##### 2 Answers

Jun 5, 2015

So:

Jun 8, 2015

Use the trig identity: c^2 = a^2 + b^2 - 2ab.cosC

400 = 121 + 196 - 308.cos A

Next, find cos B.

196 = 400 + 121 - 440.cos B

C = 180 - A - B = 180 - 105.66 - 42.38 = 31.96