Answer:
There are 271.74 ft^2 not covered by the rug
The percentage not covered by the rug is 90.58%
Step-by-step explanation:
step 1
Find out the area of the room
The area of the rectangular room is
![A=(15)(20)=300\ ft^2](https://tex.z-dn.net/?f=A%3D%2815%29%2820%29%3D300%5C%20ft%5E2)
step 2
Find out the area of the circular rug
The area of the circle is
![A=\pi r^{2}](https://tex.z-dn.net/?f=A%3D%5Cpi%20r%5E%7B2%7D)
we have
![\pi =3.14](https://tex.z-dn.net/?f=%5Cpi%20%3D3.14)
----> the radius is half the diameter
substitute
![A=(3.14)(3)^{2}](https://tex.z-dn.net/?f=A%3D%283.14%29%283%29%5E%7B2%7D)
![A=28.26\ ft^{2}](https://tex.z-dn.net/?f=A%3D28.26%5C%20ft%5E%7B2%7D)
step 3
Find out what percentage of the room is not covered by the rug
we know that
300 ft^2 represent the 100%
so
using proportion
Find out what percentage represent the difference (300-28.26)=271.74 ft^2
Let
x ----> the percentage not covered by the rug
![\frac{300}{100\%}=\frac{271.74}{x}\\\\x=100(271.74)/300\\\\x=90.58\%](https://tex.z-dn.net/?f=%5Cfrac%7B300%7D%7B100%5C%25%7D%3D%5Cfrac%7B271.74%7D%7Bx%7D%5C%5C%5C%5Cx%3D100%28271.74%29%2F300%5C%5C%5C%5Cx%3D90.58%5C%25)
Convert to fraction form
![90.58\%=\frac{90.58}{100}](https://tex.z-dn.net/?f=90.58%5C%25%3D%5Cfrac%7B90.58%7D%7B100%7D)
Simplify
![\frac{4,529}{5,000}](https://tex.z-dn.net/?f=%5Cfrac%7B4%2C529%7D%7B5%2C000%7D)
therefore
There are 271.74 ft^2 not covered by the rug
The percentage not covered by the rug is 90.58%