Answer:
C
Explanation:
First find the area of the entire figure.
L= 36
W = 20
Area = 36 * 20 = 720
Find the area of the left right triangle.
Height = 20
Base = 1/2 * 36 = 18
Just as an aside, let me be a little grumpy for a moment. You should never have to guess what a dimension is on a diagram. It's sloppy. However for this problem you have no choice. But you could think to complain to your teacher.
Area = 1/2 * base * height
Area = 1/2 * 18 * 20 = 180
Find the area of the bottom right triangle.
The height is 1/2 20 = 10
The base is 36
Area of the lower triangle = 1/2 * 36 * 10 = 180
Area of the shaded figure = 720 - 180 - 180 = 360