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 i**s 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...