Question

1. a methane storage sphere that is 18 feet wide has a surface area of ______ sq ft

Explanation:

Step1: Find the radius

The diameter \(d = 18\) feet. The radius \(r=\frac{d}{2}\), so \(r=\frac{18}{2}=9\) feet.

Step2: Use the surface - area formula for a sphere

The surface - area formula for a sphere is \(A = 4\pi r^{2}\). Substitute \(r = 9\) into the formula: \(A=4\pi\times9^{2}\).
First, calculate \(9^{2}=81\). Then \(A = 4\pi\times81\).
Since \(\pi\approx3.14\), \(A=4\times3.14\times81\).
\(4\times3.14 = 12.56\), and \(12.56\times81=(12 + 0.56)\times81=12\times81+0.56\times81=972+45.36 = 1017.36\)

Answer:

\(1017.36\)