A triangle has sides A, B, and C. The angle between sides A and B is pi/6π6 and the angle between sides B and C is pi/12π12. 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 29.65 sq.unit.

Explanation:

The angle between sides A and B is /_c = pi/6 =180/6=30^0c=π6=1806=300

The angle between sides B and C is /_a = pi/12 =180/12=15^0a=π12=18012=150

The angle between sides C and A is

/_b = 180-(30+15)=135^0 , B=18b=180(30+15)=1350,B=18 Applying sine law we get

A/sina = B/sinb or A= B*sina/sinb= 18 *sin15/sin135 ~~ 6.59Asina=BsinborA=Bsinasinb=18sin15sin1356.59

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

/_c = 30^0c=300 . Area of the triangle is A_t=(A*B*sinc)/2At=ABsinc2 or

A_t=(6.59*18*sin30)/2 ~~ 29.65 At=6.5918sin30229.65 sq.unit [Ans]