Use the area of the rectangle to find the area of the triangle.
4 ft
8 Ft

The area of the triangle is 16 feet because the are of the rectangle is 32 feet.

Step-by-step explanation:

The length of the rectangle is 8 feet. Since the dotted line is exactly in the middle of the rectangle, the bottom of the triangle s 4 feet. With 4 feet as the bottom and 4 as the height, we can calculate the area of one of the triangles ( 4 * 4 /2 ), so each of the triangle's area is 8 feet. Add them together, and you get 16!

whats the

m∠a is 90°

m∠b is 40°