A triangle has sides A, B, and C. The angle between sides A and B is pi/6 and the angle between sides B and C is pi/12. If side B has a length of 18, what is the area of the triangle?

1 Answer
Aug 12, 2017

Area of the triangle is 29.65 sq.unit.

Explanation:

The angle between sides A and B is /_c = pi/6 =180/6=30^0

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-(30+15)=135^0 , B=18 Applying sine law we get

A/sina = B/sinb or A= B*sina/sinb= 18 *sin15/sin135 ~~ 6.59

Now we have side A = 6.59 , B=18 and their included angle

/_c = 30^0 . Area of the triangle is A_t=(A*B*sinc)/2 or

A_t=(6.59*18*sin30)/2 ~~ 29.65 sq.unit [Ans]