Question

If sides A and B of a triangle have lengths of 7 and 4 respectively, and the angle between them is `(3pi)/4`, then what is the area of the triangle?

Answer 1

`:. color(orange)("Area of " Delta A_t =color(brown)(9.9 " sq units"`

Explanation:

`a = 7, b = 4, hat C = (3pi)/4`

Now we know the measure of two sides and the included angle.

`:. "Area of " Delta A_t = (1/2) a b sin C`

`A_t = (1/2) * 7 * 4 * sin ((3pi)/4) = color(brown)(9.9 " sq units"`