Question

A triangle has sides A, B, and C. Sides A and B are of lengths `4` and `8`, respectively, and the angle between A and B is `pi/3`. What is the length of side C?

Answer 1

`c=4sqrt3`

Explanation:

The formula to be used is `cos C= (a^2 +b^2 -c^2)/(2ab)`

Given information is a=4, b=8 angle C= `pi/3`

Accordingly `1/2 = (16+64 -c^2)/ 64`

`32= 80-c^2`

`c^2 =48`

`c=4sqrt3`