Question

An exercise ball has a diameter of 25 in. How many square inches of rubber are used to make the ball in terms of pi

Answer 1

we are given the diameter = 25 in

we are request to find

How many square inches of rubber are used to make the ball

since we are requesto to find square inches of rubber, we will find the surface area of the sphere

the surface area of a sphere is given by the following

`SA=4\pi r^2`

Since Diameter=2r

r= diameter/2= 12.5in

then

`SA=4*\pi *12.5^2`
`SA=625\pi`

then

it is required 625pi inches^2 of rubber to make the ball