Find the Surface Area of a Sphere

The one good thing about a sphere, it always bounces back!

 

 

A sphere is a perfectly rounded three-dimensional circular solid.

 

Unless you work in a very specialised field, you are unlikely to need to find the surface area of a sphere.

However, you do need it for maths classes. 

As ever, there is a formula to learn, but this is pretty easy to remember.

 

 

Can you remember the formula for the area of a circle? It is πr²

 

The surface area of a sphere = 4 x π x r x r or can be written as 4πr²

 

As you can see, it is just the formula for finding the area of a circle with the number 4 in front.

Remember r is the radius, which is measured from the centre of the circle to the edge.

 

Can you remember the value of π   3.142 or 3.14 is normally used in calculations. 

For this activity, use the π button on your calculator.

 

It is best for this level of work to use a scientific calculator, as you can put everything into the calculator at once without trying to work things out first.

 

Let's get started!

 

 

Find the surface area of this sphere.

 

Surface area = 4 x π  x r x r

                        4 x π  x 8 x 8 = 804 cm²

 

As we are working with area, we always answer in units²

This is all there is to it, you just have to learn the formula.

 

Let's roll on...