Question

Angela goes to the garden. There is a fountain. A circular fountain with a 10m radius lies alone in the center of a circular park with a 200 m radius. Calculate the total walking area available to the park visitors.

Answer 1

First find the area of the garden then subtract the area of the fountain. This will leave the walking area.

Fountain
A = pi * 10^2
A = 100pi

Garden
A = pi * 200^2
A = 40,000pi

40,000pi - 100pi = 39,900 m^2

Answer 2

Area of circle = pi × radius^2
Walking area = Area of garden - area occupied by fountain
Area of garden = 3.14... × 200^2
= 40000pi
Area occupied by fountain = 3.14... × 10^2
= 100pi
Walking area = 40000pi - 100pi = 39900pi
= 125349.5469 m^2