is a rectangle with sides of 40m and 20m, in the upper right corner a right triangle has been removed with the legs of: 40 - 32 = 8m and 20 - 16 = 4m, we find the area of the rectangle (b * h).
40 * 20 = 800m ^ 2, then we find the area of the right triangle
1/2 b * h: 1/2 8 * 4 = 16 m ^ 2.
we remove the area of the triangle from the rectangle and we have the area of the figure: 800 - 16 = 784m^2
