Question

What is the radius of a sphere with a surface area of 100 pi cm2

Answer 1

I think it is around 23

Answer 2

The surface area of a sphere is 4r^2pi, so dividing 100 by 4pi gives a result of 25/pi.  Taking the square root and rationalizing the denominator, we have 5sqrt(pi)/pi as the radius of the sphere.