Question

Mary is making a pinata that has a ball-like shape. The pinata has a surface area of 40 feet. Use the formula for the surface area of a sphere: (S=4πr^2) to find the radius of the pinata. Round your answers to the nearest hundredth.

Answer 1

$S=4\pi r^2\ \ \ and\ \ \ S=40\ [feet]\ \ \ \Rightarrow\ \ \ 4\pi r^2=40\ /:4\pi\\ \\r^2= \frac{10}{\pi} \ \ \ \Rightarrow\ \ \ r= \sqrt{ \frac{10}{\pi}} \ \ \ \Rightarrow\ \ \ \ r\approx1.78\ [feet]$