Question

Two flat, circular plates are placed on a circular tabletop. The diameter of each plate is equal to the radius of the tabletop. How many square inches of the tabletop are NOT covered by the plates? Use 3.14 for pi. Show your work, round your final answer to the nearest tenth, and label your answer with the correct units for area.

Answer 1

Explanation:

area of circle=pi*radius^2

tabletop area=pi*(30/2)^2=pi*15^2

plate area=pi*(15/2)^2=pi*7.5^2

NOT covered area=tabletop-2*plates

=pi*15^2-2*pi*7.5^2

=3.14*15^2-2*3.14*7.5^2

=352.25

=353.3 sq.in.

Answer 2

Area = 353.3 in^2

Explanation:

The area not covered by plates = Tabletop area - 2 x plate area

= pi x (Tabletop radius^2 - 2 x plate radius^2)

= 3.14 x ((30/2)^2 - 2 x (30/2/2)^2)

= 353.25 in^2

= 353.3 in^2