Question

Anna cuts four identical circles from a square piece of black poster board as shown. What is the area of the left over poster board? Use 3.14 for pi.

Answer 1

A) 3.44 square feet

Explanation:

The area of the black poster board would be

A = 4(4) = 16 square feet.

There are 4 identical circles in the poster board. The formula for the area of a circle is

A = πr²

Since there are 2 circles across the width of the poster board, this means two diameters are 4 feet. This makes each diameter 2 feet. The radius of a circle is half of the diameter; this makes the radius 1 feet. This gives us

A = π(1²) = 3.14(1²) = 3.14

This is the area of each circle. There are 4 circles in the poster board; this makes

4(3.14) = 12.56

This makes the left over area

16-12.56 = 3.44 square feet

Answer 2

Formula for a circle: A=Pi*r^2
Diameter:2ft
Radius:1ft
A=3.14*1^2
A=3.14
Multiply by 4
4 squares=12.56ft squared
Formula for a square: A=s^2
A=4^2
A= 16ft squared
To find leftover you need to subtract 12.56 ft from 16 ft to get 3.44 ft squared(A).