Question

Tori is studying Japan and decides to paint a Japanese flag. She first paints a white rectangle that is 36 inches long and 24 inches wide. Then in the center , she paints a red circle with a circumference of 43.96 inches. Use 3.14 for pi.

A) In the finished painting , how many square inches is the white area? Round your answer to the nearest tenth.

b) In the finished painting , how many square feet is the white area? Display two different ways to get your answer. Round your answer to the nearest hundredth.

Answer 1

First compute the area of the rectangle:

`24*36=864inches^2`
We have to find the radius of the circle:
circonférence of circle given radius is:
`C=2\pi r`
We get the equation:
`2\pi r=43.96`
Solving the above equation for r we get:
`r=7`
Compute the area of the circle like this:
`\pi r^3=\pi7^2=154inches^2`
The white area is the difference of the area of the rectangle and the area of the circle:

`864-154=710inches^2`