In summary, you just multiply the percentage (move the decimal twice to the left) by the amount, which is 70 in this case.
0.47 x 70 = 32.9
The answer is B. 3
It is the only value not attached to a variable, thus remaining constant.
The area of a circle is area = pi x r^2
The full area = 3.14 x 20^2 = 1256 square feet.
The corner forms a 90 degree angle so the dirt area is 3/4 of a full circle.
Answer = 1256 x 3/4 = 942 square feet