Question

A triangle has sides A, B, and C. Sides A and B are of lengths `3` and `1`, respectively, and the angle between A and B is `pi/12`. What is the length of side C?

Answer 1

`c=2.0505units`

Explanation:

Use the law of cosine which is
`c^2=a^2+b^2-2abcosC`

`c=sqrt(a^2+b^2-2abcosC)`
`c=sqrt(3^2+1^2-2(3)(1)cos(pi/12))`
`c=sqrt(9+1-6cos(pi/12))`
`c=sqrt(10-6cos(pi/12))`
`c=2.0505units`