A triangle has sides A, B, and C. Sides A and B have lengths of 7 and 12, respectively. The angle between A and C is (pi)/8 and the angle between B and C is (3pi)/8. What is the area of the triangle?

1 Answer
Aug 26, 2016

The Area of the Delta=42sq. units.

Explanation:

We denote, by hat(A,B), the angle btwn. sides A, and, B.

From Geometry, we know that, in any Delta

hat(A,B)+hat(B,C)+hat(C,A)=pi

:. hat(A,B)+3pi/8+pi/8=pi rArr hat(A,B)=pi/2.

Thus, given Delta is a right-triangle, and, sides A and B,

having lengths 7 and 12 resp. are at right angle.

Accordingly, the Area of the Delta=1/2712=42 sq. units.