I don't really have a calculator on me. But I'll tell you how to go through it. So the formula for the area of a circle is Pi x radius^2. So since the diameter is 36, divide that by 2 to get the radius, and you're left with 18. Now do 18 squared and then times that by Pi. Now you've got the area of the whole circle, but since we only have a semicircle, you need to divide your answer by two to get the area of the semi circle
