# Lesson video

In progress...

Hi everyone, thank you for joining me.

My name is Ms Jeremy.

Today's Maths lesson is focused on consolidating our learning of 3D shapes.

Let's start by looking at our lesson agenda.

We're going to start with a warmup today where we will recap 3D vocabulary, we'll then look at describing 3D shapes, and then the properties of 3D shapes, and we'll apply our understanding of 3D shapes to some problems before your independent task and quiz at the end of the lesson.

For today's lesson, you will need a pencil and some paper and a nice quiet space.

Feel free to pause the video now to find these resources, and once you're ready, press play to begin the lesson.

Let's begin by looking at some of the terminology that we use to describe 3D shapes.

On the left hand side here in purple, you can see all of the names that we use to describe some of the parts of 3D shapes.

And on the right, you've got the different definitions.

Let's say those purple words first.

Face.

Edge.

Vertex.

Vertices.

Apex.

What I'd now like you to do is in a moment, pause the video and can you match each of those terms to their definitions on the right hand side.

Pause the video now to do this and resume it once you're ready.

So let's have a look together.

So first of all, let's look at this word face.

Well face of a 3D shape is a flat or curved surface on the 3D shape.

In an example, like for example, a cone, you have a flat surface, which is a circular base, and then you've got the curved surface that goes all the way around the edge of the cone.

So you can have flat surfaces or flat faces and curved faces.

An edge is the area where two faces meet.

And a vertex is the corner where the edges meet.

If you have more than one vertex, we refer to this as vertices.

And the apex is a type of vertex, it's at the very top of the shape.

Not all 3D shapes have apexes.

But a shape like a cone, or a pyramid usually does have an apex, and this is located opposite the base of the shape.

Let's use some of this vocabulary to label these shapes.

You've got two shapes on the screen here, and I'd like you to use the sentence starters to determine how many faces, edges and vertices, each of these shapes has.

Spend a little bit of time having a look now.

Can you identify what these shapes are and the faces, edges and vertices that they have? I'm going to give you 10 seconds.

Okay, so looking at the first shape, this is our square-based pyramid, square-based pyramid.

And the reason we call it a square-based pyramid rather than just a pyramid is that there are different types of pyramids that you can find.

You can have a triangular-based pyramid, also called a tetrahedron.

And that's got a triangle at the bottom.

Whereas here in this case, you can see there's a square at the bottom of the pyramid.

Let's look at our square based pyramid.

First of all, we need to know how many faces it has.

I'm going to label them using this pen here.

So I've got one face there, another here, so that's two, one at the back, which is three, and then four.

And we've got the bottom, the very base as well.

So we've got five.

This has five faces.

Let's look at the number of edges now as well.

So using a different colour pen, let's see if we can label those.

So the edges are demarcated by those lines, and I'll just draw on them.

So I've got one edge here, two, three, four, five, six, seven, eight.

So we've got eight edges here on our square-based pyramid.

And finally, let's look at those vertices.

We've got one at the top, that's called our apex, two, three, four, five.

We've got five vertices on our square-based pyramid.

Now let's look at our second shape.

The second shape is called a cylinder, a cylinder.

Now cylinder has three faces.

Two of the faces are at the top and the base of the shape and they are flat.

They are circular, flat faces.

One of the faces is a rounded face that goes all the way around the edge, and we would call it a curved face.

There are three faces on a cylinder.

A cylinder has two edges.

These edges are just here and here, and they match the curved face to the flat faces.

There are no vertices, there are no corner points on the cylinder.

How did you get on with those? Did you manage to find all of the properties of those ones? So let's have one more practise of this.

I would like you to have a look at the shapes on your screen.

Can you name them? And can you also identify the number of faces, edges and vertices that they have? Pause the video now to complete your task and resume it once you're finished.

So how did you get on with that? Let's have a look at the answers.

So you should have seen the first shape here is called a sphere.

This is how we spell sphere.

And the second shape here is called a cuboid.

It is different to a cube, which makes use of square faces whereas a cuboid has rectangular faces, alongside sometimes square faces as well.

A sphere has one face.

It has one curved face, it does not have vertices, it does not have edges.

A cuboid is slightly different.

It has six faces, four the gird on the outside, one at the top, one at the bottom.

So six faces in total.

In terms of the number of edges, it has twelve edges, and it has eight vertices.

How did you get on with those? Did you get those all correct? So let's move on to another independent task for you to complete.

As you can see on the screen, we have five shapes.

Let's label these shapes.

We've got the shape a, which is called a square-based pyramid.

Shape b is called a cylinder.

Shape c is a cone.

Shape d is a triangular prism, and shape e is a cuboid.

So we're going to look at the different properties that these shapes have.

I would like us to divide these shapes into two different groups according to their properties.

And I want you to tell me, what could the groups be? How could we divide these up? So I'm going to give you an example.

We could have two groups, the first group could have all of the shapes that have only flat faces.

And the second group could have shapes that have curved and flat faces.

So the shapes that would need to go into the first group were only shapes with flat faces are located would be shapes a, e and d.

These shapes only have flat faces.

In the second group, where we can place shapes that have flat and curved bases, we could place shapes b, and c.

Can you create your own two groups in the same way that I've done using either properties related to faces, vertices, or edges? Pause the video now to complete your task and resume it once you're finished.

How did you get on with that activity? Did you manage to find two different groups that you could place these shapes into? How many shapes did you manage to put into each group? So one more thing I'd like us to have a look at is some riddles related to 3D shapes as well.

Let's have a look at the first riddle.

It says this shape has six rectangular faces, what is the shape? What else can you tell me about it? So I'd like you to think about what could this shape be? It's got six rectangular faces.

What is it? And what can you tell me about it? So you might have known that this shape is a cuboid.

If it's got six rectangular faces, it must be a cuboid.

And you might also be able to tell me that in addition to its six rectangular faces, it has 12 edges and it also got eight vertices.

Looking at the second example now, it says the shape has zero vertices and zero straight edges.

What is the shape? Well, you might have chosen more than one option.

I've chosen in this case, a sphere because a sphere has one curved face, it doesn't have any vertices, doesn't also have any straight edges either.

So the other thing you might be able to explain about the shape is that it has only one face.

You might have chosen to go for an example like a cylinder instead, that also would have been correct in this case.

So one more example of an independent task I'd like you to practise before we move on to our final task for the day.

This one says I have some shapes in a bag.

In total, there are 12 faces and 12 vertices, what could my shapes be? So you've got to imagine that out of the selection in front of you, and these are the shapes that we've been looking at today.

In this bag, there are a few shapes, I'm not going to tell you how many there were yet, and you've got to work out which of those shapes might be in the bag if there were 12 faces, and 12 vertices in total? Pause the video now to complete your task and resume it once you're finished.

So how did you get on? Did you manage to find the different shapes that would produce 12 faces and 12 vertices if they're in a bag? So what you might have got, the solution you might have got was using a cone, a triangular prism and a square-based pyramid.

Let me show you how that might have produced 12 faces and 12 vertices.

So on our cone, we've got two faces.

For our triangular prism, we've got five faces.

And for a square-based pyramid, we've got five faces, that is a total of 12 faces.

Let's look at the vertices.

So here on our cone, we've got one vertex.

On our triangular prism, we've got one, two, three, four, five, six vertices.

And for our square-based pyramid, let's count them, we've got the apex one, and then two, three, four, five, we've got five there, five vertices there.

So we've got one plus six plus five, which is equal to 12.

So that was 12 vertices and 12 faces in the same bag.

Did you manage to get the same answer as me? Okay, so moving on to our very final task or independent tasks, which is going to be a fun one today, I would like you to have a look at the table and you can see that we've got four shapes that I've written down.

A cuboid, a triangular prism, a cone and a cylinder.

Your task is spend 10 minutes wandering around your house to see whether you can find as many items as possible that use these shapes in some form or another.

So, for example, I had a look around my house this morning and I found that I had a chocolate box that was in the shape of the cuboid.

So I write chocolate box here.

A triangular prism, I found that my hairbrush handle was in the shape of a triangular prism.

For the cone, I found a party hat in one of my cupboards, and so I put this down for our cone.

And for a cylinder my rubbish bin is shaped like a cylinder.

So I managed to find four items that use those 3D shapes.

What I'd like you to do is to see how many different items you can find that use these shapes.

And then also, fill out the properties of these different 3D shapes.

I want to know the number of faces, the vertices and also edges that each of these shapes have.

Pause the video to complete your task and resume it once you're finished.

How did you get on? Did you manage to find lots of those 3D shapes included within your household items? Fingers crossed, hopefully you managed to do that.

And it'd be great to see some of these shapes and some of these ideas that you've got and also the properties that you found for each of the 3D shapes.