area=pi times radius squared or a=pi times r^2
diameter=2r
diameter=18
radius=1/2diameter
radius=1/2(18)=9
area=pi times 9^2
area=pi times 81
81π feet squared is the answer
aprox pi=π to 3.14 and do
81 times 3.14=254.34
the answer is closest to 254.34 square ft