Question

Given a sphere with radius r, the formula 4r2 gives _____.

Answer 1

the surface area

Explanation:

Answer 2

The answer is: The surface area of the sphere.

The explanations for this exercise is shown below:

By definition, the surface area of a sphere is four times the area of a circle.

You have that the area of a circle is:

`A=\pi r^(2)`

Where
`r` is the radius of the circle.

Therefore, to calculate the surface area of a sphere with radius
`r`, you only need to multiply the equation shown above by four, as following:

`image`