Question

Find the surface area of a grapefruit with a circumference of 14 cm. Round your answer to the nearest whole number.

Answer 1

The answer is 62 cm^2!

Answer 2

The circumference is given by $2 \pi r=14\;cm$. The radius is

$r=\frac{7}{\pi}$. The surface area of the grape fruit is

$S=4\pi r^2$.

Substituting numerical values,

$S=4\pi (\frac{7}{\pi}) ^2\\ S=615.75\;cm^2\\ S = 616\;cm^2$