The formula to find the area of a circle is [tex]A=\pi r^2[/tex], where 'r' is the radius, they've given you diameter=22ft, the radius will be half of the diameter, r=11.
[tex]A=\pi r^2[/tex]
[tex]A=\pi (11)^2[/tex]
[tex]A=121 \pi[/tex]
[tex]A \approx 380ft[/tex]
