- Three dimensional,

or 3D shapes, are shapes that take up space.

They have three dimensions,

length, width and height.

The world is made up of 3D shapes.

They are all the things we can hold.

Your book is a 3D shape,

so is your soccer ball,

as well as your birthday presents.

Can you see how they each take up space?

There are some features that are common

across three dimensional shapes.

These features include faces,

edges and corners.

The flat surfaces of a shape are called faces.

No, not that type of face!

The edge of a 3D shape is the line

where two of its surfaces meet.

And the corner is where

two or more edges meet.

A corner can also be called a vertex.

The faces of 3D shapes often contain

2D shapes that you may already know.

Maybe you can recognise some of these 2D shapes

as we go through a few examples.

Here are some three dimensional shapes and their features.

This shape is a cube.

A cube has six faces that are identical,

twelves edges, and eight corners.

All of the faces, edges and corners

are the same size and length.

Can you see how each face of the cube is a square?

This shape is called a rectangular prism.

A rectangular prism has six faces,

twelve edges, and eight corners.

It's very similar to the cube, except instead of

all the faces being squares, they're rectangles.

The opposite faces of a rectangular prism

are always the same size.

This shape is a triangular prism.

A triangular prism has five faces,

nine edges, and six corners.

Triangular prisms have two faces that are triangles

and three faces that are rectangles.

The two triangle faces are always the same size.

However, some 3D shapes have more

than just flat surfaces.

Some have curved surfaces,

but we don't call them faces

because faces are always flat.

This shape is called a cylinder.

A cylinder has two circles on each end

that are the same size,

with a tube in the middle.

It has two flat faces, and one curved surface.

The cylinder also has two edges, but no corners.

Remember, a corner is where two or more edges meet.

In a cylinder, there are no corners

because its two edges do not meet.

This is a cone.

Not an ice-cream cone, unfortunately!

But it is the same shape.

A cone has a circle at its base,

and a point at the other end.

It has one flat face, one curved surface,

one edge around its base, but no corners.

This unique shape is a sphere.

It's perfectly round, just like a ball.

This means it has no flat faces,

no edges and no corners,

just one curved surface.

How unique is that!

That's what makes a sphere the perfect shape for a ball.

It rolls around easily in any direction

and you can kick it without banging

your toe on a sharp corner!

Now that you know some three dimensional shapes,

perhaps you can spot a few examples

of them in your classroom

or outside in the playground.