How do you the work out the area of a 3D sphere is the radius is 5cm?

Answer 1

If you means surface area of a sphere, then use this formula:

A = r^2 * pi * 4

where:

A= surface area

r=radius

pi=~3.14159

e.g.:

A = 5^2 * 3.14159 * 4

A = 25 * 3.14159 * 4

A = 100 * 3.14159

A = ~314.16 cm^2

If you actually mean volume of a sphere, then use this formula:

V = r^3 * pi * (4/3)

where:

V= volume

r=radius

pi=~3.14159

e.g.:

V = r^3 * pi * (4/3)

V = 5^3 * 3.14159 * 4/3

V = 125 * 3.14159 * 4/3

V = ~523.6 cm^3