Richard has two circular sprinklers to water his rectangular backyard, as shown.

(Richards Backyard is in the Picture)

The backyard has an area of 512 square feet.

In the first response box, enter an expression using r that represents the
exact area, in square feet, of Richard's backyard that is not watered.

In the second response box, enter the area, in square feet, of Richard's
backyard that is not watered. Round your answer to the nearest hundredth.