Question

Look at the formula for the area of a circle below.

A = r2

Which of the following equations can be used to solve for the radius (r)?

Answer 1

Isn't the formula for area of the circle \[a=\pi * r^2\]

Answer 2

so you already have

A = r²

(even though the area of a circle is pi r²)

Answer 3

You are going to need to take the square root of each side like so:\[\sqrt{a}=\sqrt{r^2} which will get you \[r=\sqrt{a}\]