Question

question 4 of 10
what is the surface area of a sphere with a radius of 9 units?
a. 576π units²
b. 648π units²
c. 288π units²
d. 324π units²

Explanation:

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

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

Step2: Substitute the given radius into the formula

Given \(r = 9\) units. Substitute \(r = 9\) into \(S = 4\pi r^{2}\), we get \(S=4\pi\times9^{2}\).

Step3: Calculate \(9^{2}\)

\(9^{2}=81\). So the formula becomes \(S = 4\pi\times81\).

Step4: Calculate \(4\times81\)

\(4\times81 = 324\). So \(S=324\pi\) units\(^{2}\).

Answer:

D. \(324\pi\) units\(^{2}\)