Question

the axis of the sphere below is 12 units in length. what is the surface area of the sphere? a. 256π units² b. 72π units² c. 144π units² d. cannot be determined

Explanation:

Step1: Identify the radius

The axis of the sphere is its diameter. Given diameter $d = 12$ units, so radius $r=\frac{d}{2}=\frac{12}{2}=6$ units.

Step2: Use the surface - area formula

The surface - area formula of a sphere is $A = 4\pi r^{2}$. Substitute $r = 6$ into the formula: $A=4\pi\times6^{2}=4\pi\times36 = 144\pi$ square units.

Answer:

C. $144\pi$ units$^{2}$