Answer:
[tex]\large\boxed{\dfrac{16}{81}}[/tex]
Step-by-step explanation:
The formula of an area of a circle:
[tex]A=\pi r^2[/tex]
r - radius
Circle A:
radius = 4 ft. Substitute:
[tex]A_A=\pi(4^2)=16\pi\ ft^2[/tex]
Circle B:
radius = 9 ft. Substitute:
[tex]A_B=\pi(9^2)=81\pi\ ft^2[/tex]
The ratio:
[tex]\dfrac{A_A}{A_B}=\dfrac{16}{81}[/tex]
