Question

Calculatebthe surface of a sphere with diameter 25 inches.

Answer 1

The surface area of a sphere is given by the formula

`SA=4\pi r^2`

where

r=25/2=12.5 in -----> the radius is half the diameter

substitute

`\begin{gathered} SA=4\pi(12.5)^2 \\ SA=625\pi\text{ in}^2\text{ ----> exact value} \end{gathered}`

Find out the approximate surface area

`\begin{gathered} SA=625\pi \\ SA=1,963.50\text{ in}^2\text{ ---> approximate value rounded to two decimal places} \end{gathered}`

The answer is 1,963.5 in2