Question

A triangle has sides A, B, and C. Sides A and B are of lengths `2` and `1`, respectively, and the angle between A and B is `(7pi)/8`. What is the length of side C?

Answer 1

side `c=2.95" "`units

Explanation:

Given
side `a=2` and side `b=1` and angle `C=(7pi)/8`

by Cosine Law for sides

`c=sqrt(a^2+b^2-2*a*b*cos ((7pi)/8))`

`c=sqrt(2^2+1^2-2*(2)*(1)*cos ((7pi)/8))`

`c=2.9488163947668" "`units

God bless...I hope the explanation is useful.