The radius of the circle increases by 4 feet per minute. When 1 minute has passed, the radius is 4 feet, and when 5 minutes have passed, the radius will be 5 times that:
[tex]4\times5=20[/tex]The radius of the circle after 5 minutes is 20 feet.
To find the area, we use the formula for the area of a circle:
[tex]A=\pi r^2[/tex]Using the radius of 20 feet:
[tex]r=20ft[/tex]And substituting it into the formula for the area:
[tex]\begin{gathered} A=\pi(20ft)^2 \\ A=\pi(400ft^2) \end{gathered}[/tex]Using:
[tex]\pi=3.1416[/tex]We get the are of the circular pattern:
[tex]\begin{gathered} A=(3.1416)(400ft^2) \\ A=1,256.64ft^2 \end{gathered}[/tex]Answer:
[tex]\begin{gathered} r=20ft \\ A=1,256.64ft^2 \end{gathered}[/tex]