A triangle has sides A, B, and C. Sides A and B have lengths of 5 and 8, respectively. The angle between A and C is (pi)/12 and the angle between B and C is (5pi)/6. What is the area of the triangle?

1 Answer
Mar 27, 2018

color(red)(A_t = (1/2) a b sin C = (1/2) * 5 * 8 * sin (pi/12) = 5.18 " sq units"

Explanation:

a = 5, b = 8, hat A = (5pi)/6, hat B = pi/12

To find the area of the triangle.

hat C = pi - (5pi)/6 - pi/12 = pi/12

It's an isosceles triangle with hat B = hat C " & hence " b = c = 8

![https://www.onlinemathlearning.com/http://area-triangle.html](https://useruploads.socratic.org/09L4f2StTbKqkH4UI3LT_area%20of%20triangle.png)

Formula for Area of triangle, knowing 2 sides and included angle

color(red)(A_t = (1/2) a b sin C = (1/2) * 5 * 8 * sin (pi/12) = 5.18 " sq units"