Question

A triangle has sides A, B, and C. Sides A and B are of lengths `7` and `4`, respectively, and the angle between A and B is `(7pi)/12`. What is the length of side C?

Answer 1

The length of side C is 8.91 unit

Explanation:

Here the sides a= 7 ; b=4 and their included angle is `C=7*180/12=105^0` We know
`c^2 = a^2+b^2-2*a*b*cos(C)` or `c^2=7^2+4^2-2*7*4*cos(105)`
or `c^2 = 49 +16 -56*(-0.2588)` or`c^2=79.49` or `c= 8.91`[answer]