-- What I Did --
First, I plugged in the numbers in the equation. A = 40m2.
I then solved the equation inside of the square root. So I did 40m2/π.
Rounded to the nearest hundreth place, 40/π = 12.73
You must now solve the equation of the square root of 12.73.
So, R= 3.6m, rounded to the nearest tenth.
A link to squares and square roots
A video to square roots: