Take note of the formula for the area of a rectangle.
We ahve two rectangle with width = 2cm, and length = 4cm.
Area of those two rectangles is:
A = 2(L*W) = 2(4*2) = 16 cm^2.
Get the area of the rectange with lenght = 5cm, and width = 2cm.
A = 5 * 2 = 10 cm^2
Adding the results.
Area of the shaded region will be:
A = 16 cm^2 + 10 cm^2 = 16 cm^2.