Question

A triangle has sides A, B, and C. The angle between sides A and B is `(7pi)/12`. If side C has a length of `16` and the angle between sides B and C is `pi/12`, what is the length of side A?

Answer 1

`4.29`

Explanation:

sine rule: `a/sin A = b/sin B = c/sin C`

`c` / `sin` (angle between A and B) = `a` / `sin` (angle between B and C)

`16/sin((7pi)/12) = a/sin(pi/12)`

multiply both sides by `sin (pi/12):`

`a = (16sin(pi/12)) /sin((7pi)/12)`

`= 4.29` (`3` s.f.)