Question

If the great circle circumference of a sphere is 16 pi yards, find its surface area.

Answer 1

`\text{Circumference of a sphere = 16}\pi`
`\text{Surface area of a sphere = 4}\pi r^2`
`\begin{gathered} \text{Circumference = 16}\pi \\ Fi\text{ nd the radius r from the circumference} \\ 2\pi r\text{ = 16}\pi \\ \text{Divide through by 2}\pi. \\ (2\pi r)/(2\pi)\text{ = }(16\pi)/(2\pi) \\ r\text{ = 8} \end{gathered}`

Next, find the surface area.

`\begin{gathered} \text{Surface area = 4}\pi r^2 \\ \text{ = 4}\pi\text{ }*8^2 \\ \text{ = 4}\pi\text{ x 64} \\ \text{ = 256}\pi yd^2 \end{gathered}`