Question

A circle with radius of 4 cm sits inside a circle with radius of 11 cm.

What is the area of the shaded region?
Round your final answer to the nearest hundredth.​

Answer 1

The area of the shaded region = 330 sq cm

Explanation:

Given,

The radius of small circle (r) = 4 cm

The radius of large circle (R) = 11 cm

To find the shaded region

Formula

The area of circle of radius r = π
`r^(2)` sq cm

So, The radius of the small circle = π×
`4^(2)` sq cm = 16π sq cm

The radius of the large circle = π×
`11^(2)` sq cm = 121π sq cm

Hence the area of the shaded region = 121π-16π sq cm

= 105π sq cm

= 105 ×
`(22)/(7)` sq cm = 330 sq cm

Answer 2

Answer: 329.7

Explanation:

Area of circle = \pir^{2}

Area of circle with radius of 4 cm = 3.14 * 4 * 4 = 50.24

Area of circle with radius of 11 cm = 3.14 * 11 * 11 = 379.94

Their difference = 329.7