The area of the circle is (pi)*radius^2. The radius is half of the diameter which is given as 5 feet so it equals 2.5 feet. This is equal to (5/6) of a yard since 1 yard is 3 feet. Therefore, the area of the circle is (pi)*(5/6)^2 = 2.182 square yards to three decimal places.
If you mean the volume of a cylinder with this area circle and with a depth of 2 feet, which is (2/3) of a yard, the volume is (2/3) * 2.182 = 1.45 cubic yards to two decimal places.