Question

A ballon has a circumference of 28 in use the circumference to approximate the surface area of the ballon to the nearest square inch

Answer 1

Seeing that no one has given an answer this is my attempt:

The circumference is
\[28=2\pi r\]
Rearranging yields
\[r=\frac{14}{\pi}\]
The surface area for a sphere is:
\[S=4\pi r^{2}\]
Substituting \(r=\frac{14}{\pi}\) gives
\[S=4\pi \frac{14}{\pi} \frac{14}{\pi}=\frac{784}{\pi}\]