Question

The formula for the area of a circle is A=πr^2.
If the area of a circle is represented by A=21π, what is the radius of the circle?
Round your answer to the nearest tenth.

Answer 1

The Area of the circle is \[A=\pi r^2\]

Answer 2

Work backwards. Given A, find r.

First, reverse the above equation:\[\pi r^2 =A\]

Answer 3

Divide both sides by pi

Find the square root of both sides of the resulting equation. Show your work, please.