A triangle has sides A, B, and C. The angle between sides A and B is (5pi)/12 and the angle between sides B and C is pi/12. If side B has a length of 36, what is the area of the triangle?

1 Answer
Apr 10, 2018

:.color(brown)(A_t = (1/2) * a * c = (1/2) * 9.32 * 34.77 = 162.06 " sq units"

Explanation:

hat A = pi/12, hat C = (5pi)/12, hat B = pi - pi/12 - (5pi)/12 = pi/2, b = 36

It's a right triangle with hat B = 90^@

As per the Law of Sines,

color(purple)(a / sin A = b / sin B = c / sin C)

:. a = (b * sin A) / sin B = (36 * sin (pi/12)) / sin (pi/2) = 9.32

:. c = (b * sin C) / sin B = (36 * sin ((5pi)/12)) / sin (pi/2) = 34.77

:.color(brown)(A_t = (1/2) * a * c = (1/2) * 9.32 * 34.77 = 162.06 " sq units"