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 33, what is the area of the triangle?

1 Answer
May 31, 2017

The area of triangle is 136.1 (1dp) sq.unit

Explanation:

The angle between sides A and B is /_c = (5pi)/12=(5*180)/12=75^0

The angle between sides B and C is /_a = pi/12=180/12=15^0

The angle between sides C and A is /_b = 180-(75+15)=90^0

Applying sine law we can find A/sina=B/sinb ; B=33 :. A/sin15=33/sin90 or A= 33*sin 15~~8.54(2 dp); [sin 90 =1]

Now we know the adjacent sides A , B and their included angle /_c.

The area of triangle is A_t =(A*B*sin c)/2= (8.54 * 33*sin 75)/2 ~~ 136.1(1dp) sq.unit