A triangle has sides A, B, and C. The angle between sides A and B is (7pi)/127π12 and the angle between sides B and C is pi/12π12. If side B has a length of 34, what is the area of the triangle?

1 Answer
Dec 24, 2017

Area of the triangle is 166.83166.83 sq.unit.

Explanation:

Angle between Sides A and BAandB is /_c= (7pi)/12=105^0c=7π12=1050

Angle between Sides B and CBandC is /_a= pi/12=180/12=15^0 :.

Angle between Sides C and A is /_b= 180-(105+15)=60^0

The sine rule states if A, B and C are the lengths of the sides

and opposite angles are a, b and c in a triangle, then:

A/sina = B/sinb=C/sinc ; B=34 :. A/sina=B/sinb or

A/sin15=34/sin60 :. A = 34* sin15/sin60 ~~ 10.16(2dp)unit

Now we know sides A=10.16 , B=34 and their included angle

/_c = 105^0. Area of the triangle is A_t=(A*B*sinc)/2

:.A_t=(10.16*34*sin105)/2 ~~ 166.83 sq.unit

Area of the triangle is 166.83 sq.unit [Ans]