Question

What is the radius of a sphere that has a surface area of 12.56 in2? use 3.14 for pi. recall the formula sa=4 pi r 2?

Answer 1

SA=4pir²

given SA=12.56

12.56=4pir²
divide both sides by 4
3.14=pir²
3.14=3.14r²
divide both sides by 3.14
1=r²
sqrt both sides
1=r
the radius is 1 in

Answer 2

`r=1 in`

Explanation:

Given: The surface area of a sphere is
`12.56 in^2`.

To find: The radius of the sphere.

Solution: It is given that the surface area of a sphere is
`12.56 in^2`, thus we have

`S.A=4{\pi}r^2` where r is the radius of the sphere.

⇒
`12.56=4(3.14)(r)`

⇒
`12.56=12.56r`

⇒
`(12.56)/(12.56)=r`

⇒
`r=1 in`

Therefore, the radius of the sphere is 1 inches.