The area of a sector is 9pi cm^2 . The sector cover 1/4 of the entire circle. Find the radius of the circle. Thank you.

Given:

The area of a sector =

The sector cover of the entire circle.

To find:

The radius of the circle.

Solution:

Let r be the radius of the circle. Then, the area of the circle is:

It is given that the sector cover of the entire circle. So, the area of the sector is equal to of the area of the entire circle.

Multiply both sides by 4.

Divide both sides by .

Taking square root on both sides.

Radius of a circle cannot be negative. So, .

Therefore, the radius of the circle is 6 cm.

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify