A circle has an area of 40 square meters. Which answer is closest to the measure of its diameter?

The formula is a=pi r^2

Plug in 40 for the area.

40 = pi r^2

Divide both sides by pi to get the r^2 isolated.

(40/pi) = r^2

To clear the r^2 to r you take the square root of each side resulting in

r=3.568