Question

A sphere has a diameter of 12 ft. What is the surface area of the sphere? Express the answer in terms of pi.

Recall the formula SA=4 pi r^2.


pi ft^2

Answer 1

the answer is 144 pi^2

Answer 2

`SA=144\pi\ ft^2`

Explanation:

We know that the diameter of the sphere is 12 feet.

By definition the radius of the sphere is:

`r =(d)/(2)`

Where d is the diameter of the sphere

Then

`r =(12)/(2)`

`r =6\ ft`

Now we calculate the surface area of the sphere using the formula

`SA=4\pi r^2`

`SA=4\pi (6)^2`

`SA=4\pi(36)`

`SA=144\pi\ ft^2`