The horse describes a circle with radius 22.
The area for a circle with radius [tex]r[/tex] is [tex]A=\pi r^2[/tex]
So, in your case, we have
[tex]A=\pi r^2 = 22\cdot 22\cdot\pi=484\pi[/tex]
Since [tex]\pi\approx 3.14[/tex], we have
[tex]A\approx 484\cdot 3.14=1519.76[/tex]
If we have to round this to the nearest square foot, we have 1520.