Question

Find the approximate radius of a sphere with a surface area of 400 square inches.

Answer 1

The equation for surface area of a sphere is SA=4*pi*r^2
We can plug in what we know to solve for r
400=4*pi*r^2
100=pi*r^2 (divide out the 4)
100/pi=r^2 (divide out the pi)
√(100/pi)=r (square root of both sides)
r=5.6 rounded to the nearest tenth