Question 20 of 33 What is the surface area of the sphere shown below with a radius of 7?
1.72
A. 495 sq. units
B. 65x sq, units
C. 457 sq. units
D. 1965 sq. units
SERNAT

The surface area of the sphere 1s 615.75 sq. unit.

Step-by-step explanation:

The surface area of a sphere = 4·π·r²

Given that the radius of the sphere = 7, we have

The surface area of the sphere = 4 × π × 7^2 =  615.75 sq. unit    

The surface area can also be derived from the volume of the sphere by differentiation as follows;

Volume of a sphere, V = 4/3·π·r³

(The volume of the sphere is 4/3·π·7³ = 1436.76 cube unit)

dV/dr = d(4/3·π·r³)/dr = 3×4/3·π·r² = 4·π·r²

The surface area of the sphere = 615.75 sq. unit.