Answer:
[tex]\large\boxed{C=22\pi y\ ft}[/tex]
Step-by-step explanation:
The formula of an area of a circle:
[tex]A=\pi r^2[/tex]
r - radius
The formula of a circumference of a circle:
[tex]C=2\pi r[/tex]
We have the area of a circle
[tex]A=121y^2\pi ft^2[/tex]
Substitute to the formula and solve for r:
[tex]\pi r^2=121y^2\pi[/tex] divide both sides by π
[tex]r^2=121y^2\to r=\sqrt{121y^2}\\\\r=11y\ ft[/tex]
Put the value of r to the formula of a circumference:
[tex]C=2\pi(11y)=22y\pi ft[/tex]
