Geometry

Surface Area of a Sphere

Sphere Surface Area Formula

The formula for surface area of a sphere is given as:
SA = 4πr2
Where SA is the surface area and r is the radius of the sphere.

surface area of a sphere

Example Problems

Problem 1:
Find the surface area of a sphere with a radius of 10.
Solution:
1.) Plugging what we know into the surface area formula, we get:
SA = 4πr2
SA = 4π(102) = 400π
2.) The surface area is 400π.

Problem 2:
The surface area of a sphere is measured to be 100π square meters. What is the diameter of the sphere in meters?
Solution:
1.) First, we will plug the surface area value into the formula and solve for the radius r.
SA = 4πr2
100π = 4πr2
25 = r2
r = 5
2.) Now that we have the radius, let’s convert it to diameter.
d = 2r
d = 2(5) = 10
3.) The diameter of the sphere is 10 meters.

Result :

Worksheet 1

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Cheat sheet

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