A triangle has sides A, B, and C. The angle between sides A and B is (5pi)/6 and the angle between sides B and C is pi/12. If side B has a length of 3, what is the area of the triangle?

1 Answer
Jun 3, 2018

Area color(maroon)(A_t = (1/2) * 3 * 3 * sin ((5pi)/6) = 2.25 sq units

Explanation:

Law of Sines a / sin A = b / sin B = c / sin C

Area of triangle A_t =.(1/2) a b sin C

b = 3, hat A = pi/12, hat C = (5pi)/6, hat B = pi - pi / 12 - (5pi)/6 = pi/12

It’s an isosceles triangle with angles #hat A = hat B = pi/12%

:. b = a = 3

Area color(maroon)(A_t = (1/2) * 3 * 3 * sin ((5pi)/6) = 2.25 sq units