Question

A triangle has sides A, B, and C. Sides A and B are of lengths `10` and `12`, respectively, and the angle between A and B is `(7pi)/12`. What is the length of side C?

Answer 1

c= 13.4846

Explanation:

The question to be solved is as shown in the figure

Now using cosine formula side `c^2= 100+144-2(10)(12)cos (7pi)/12`

`c^2 = 244 -240 cos 105^o`

    = 244-240(-0.2588)  =181.88

c=13.4846