Find the area of the shaded region.

8x5 = 40
3x2 = 6

40 - 6 = 34

area of shaded = 34

So you would need to subtract the area of the whole rectangle-the white area of the rectangle
The formula for area is a=bh
the area of the whole rectangle is a=8*5, so 40units squared, and the are of the non-shaded region is a=3*2 so 6 units squared
in order to find the shaded region, do 40-6
34 units squared is your answer
hope this helps!:)