Question

At a zoo, the lion pen has a ring-shaped sidewalk around it. The outer edge of the sidewalk is a circle with a radius of 11 m. The inner edge of the sidewalk is a circle with a radius of 9 m.
⦁ Write and simplify an expression for the exact area of the sidewalk.
⦁ Find the approximate area of the sidewalk. Use 3.14 to approximate π

Answer 1

Answer:

$\text{Exact area of the sidewalk}=40 \pi\text{ m}^2$

$\text{Approximate area of the sidewalk}=125.6\text{ m}^2$

Step-by-step explanation:

We have been given that at a zoo, the lion pen has a ring-shaped sidewalk around it. The outer edge of the sidewalk is a circle with a radius of 11 m. The inner edge of the sidewalk is a circle with a radius of 9 m.

To find the area of the side walk we will subtract the area of inner edge of the side walk of lion pen from the area of the outer edge of the lion pen.

$\text{Area of circle}=\pi r^2$, where r represents radius of the circle.

$\text{Exact area of the sidewalk}=\pi*\text{(11 m)}^2-\pi*\text{(9 m)}^2$

$\text{Exact area of the sidewalk}=\pi*\text{121 m}^2-\pi*\text{81 m}^2$

$\text{Exact area of the sidewalk}=40 \pi\text{ m}^2$

Therefore, the exact area of the side walk is $40 \pi\text{ m}^2$

To find the approximate area of side walk let us substitute pi equals 3.14.

$\text{Approximate area of the sidewalk}=40*3.14\text{ m}^2$

$\text{Approximate area of the sidewalk}=125.6\text{ m}^2$

Therefore, the approximate area of the side walk is $125.6\text{ m}^2$.