The diameter of a sphere measures 10.4 inches. What is the surface area of the sphere?

A. [tex]$108.16 \pi$[/tex] in[tex]$^2$[/tex]
B. [tex]$54.08 \pi$[/tex] in[tex]$^2$[/tex]
C. [tex]$216.32 \pi$[/tex] in[tex]$^2$[/tex]
D. [tex]$432.64 \pi$[/tex] in[tex]$^2$[/tex]



Answer :

To find the surface area of a sphere when given its diameter, we can follow these steps:

1. Calculate the Radius:
The radius ( [tex]\( r \)[/tex] ) is half of the diameter.

[tex]\[ r = \frac{d}{2} \][/tex]

Given the diameter, [tex]\( d = 10.4 \)[/tex] inches,

[tex]\[ r = \frac{10.4}{2} = 5.2 \text{ inches} \][/tex]

2. Surface Area Formula:
The surface area [tex]\( S \)[/tex] of a sphere can be calculated using the formula:

[tex]\[ S = 4 \pi r^2 \][/tex]

3. Substitute the Radius:
Plugging the radius [tex]\( r = 5.2 \)[/tex] inches into the formula:

[tex]\[ S = 4 \pi (5.2)^2 \][/tex]

4. Calculate the Surface Area:
First, calculate [tex]\( (5.2)^2 \)[/tex]:

[tex]\[ (5.2)^2 = 27.04 \][/tex]

Then multiply by [tex]\( 4 \pi \)[/tex]:

[tex]\[ S = 4 \pi \times 27.04 = 108.16 \pi \][/tex]

Therefore, the surface area of the sphere is [tex]\( 108.16 \pi \)[/tex] square inches.

So the correct answer is:

A. [tex]\( 108.16 \pi \)[/tex] in[tex]\(^2\)[/tex]