Need with finding the area of this

In the given figure, there are two right angled triangles.

Area of triangle = 1/2 × b × h

Area of shaded region = area of larger triangle - area of smaller triangle

= 1/2 × 15 × 18 - 1/2 × 8 × 9

= 135 - 36

= 99 ft^2

Thus, area of shaded region is 99 ft^2.

The answer to your question is b