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

##### 1 Answer

Feb 5, 2018

See explanation.

#### Explanation:

If you have 2 sides of a triangle given and the angle between them, you can use the Cosine Theorem to calculate the remaining side:

#C^2=A^2+B^2-2ABcosc#

where

If we apply the given data we have: