The formula of the surface area of a sphere is [tex]4 \pi r^{2} [/tex]
We have the diameter, but we can easily find the radius by dividing the diameter by 2.
2.5/2 = 1.25
Now, we plug this into the formula
[tex]4 \pi * 1.25^{2} =19.63[/tex]
So, you will need 19.63 square inches of material to cover the tennis ball.
