Refer to the pets problem at the beginning of this lesson finde the area ti the nearest tent. of grass that adrianne, s dog may run in if the leash is 9 feet long

The leash will serve as the radius of the circle that Adrianne's dog will be running around on. 

radius = 9 feet long

Area = π r²
Area = π (9ft)²
Area = π 81ft²

Circumference = 2 π r
Circumference = 2 π 9ft
Circumference = 18ft π

The circumference of the circle that the dog will be forming when it runs around his leash is 18ftπ and the area it will cover will be 81ft²π.