Question

the radius r of a sphere is 9.9 m. calculate the spheres surface area a. use the value 3.14 for π, and round your answer to the nearest tenth. your answer a = 307.7 m²

Explanation:

Step1: Recall the formula for the surface area of a sphere

The formula for the surface area of a sphere is \(A = 4\pi r^{2}\).

Step2: Substitute the given values

Given \(r=9.9\) m and \(\pi = 3.14\). Substitute into the formula: \(A=4\times3.14\times(9.9)^{2}\).
First, calculate \((9.9)^{2}=98.01\).
Then, \(4\times3.14\times98.01 = 12.56\times98.01\).
\(12.56\times98.01=12.56\times(100 - 1.99)=12.56\times100-12.56\times1.99\)
\(=1256-(12.56\times2 - 12.56\times0.01)=1256-(25.12 - 0.1256)\)
\(=1256 - 25.12+0.1256=1230.9944\approx1231.0\) (rounded to the nearest tenth)

Answer:

\(1231.0\space m^{2}\)