Lesson video

Hi, everyone.

Thanks for joining me.

My name is Miss Jeremy.

And today's math lesson is all about identifying the properties of constructed 3D shapes.

So find yourself a nice quiet space ready for your learning and then press play when you're ready to begin the lesson.

We'll begin with the lesson agenda for today.

So for our warmup, we're going to be matching shapes to their corresponding properties.

We're then going to recap some 3D shape vocabulary before looking at the properties of constructed 3D shapes.

You'll finish today with your independent task and quiz at the end of the lesson.

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

So feel free to pause the video now to find these resources, and then press play when you're ready to begin the lesson.

Let's start with our warm up.

Have a look at the shapes on the left hand side of your screen.

First of all, can we identify the names of these five shapes? I'm going to give you 10 seconds to see whether you can remember, all five names of all five shapes.

Okay, let's have a look together.

So the first one you should have remembered was a cube, that is a cube, it is a 3D shape, a three dimensional shape, and we call it a cube.

The second one here, which I'm going to label B is a cone, it's a cone.

And the third one here, is what we call a triangular prism.

And the reason it's called a triangular prism is that it makes use of two faces, which are triangles.

Shaped D here is a triangular based pyramid, or sometimes called a tetrahedron.

So either of those names are absolutely fine.

And shape E here is what we call a cylinder.

So some of these 3D shapes share some properties, but as you can see on the screen, we've got four different properties that have been labelled to match some of those shapes.

I wonder whether you can match each of those properties to one of those shapes on the screen.

I'm going to give you another 10 seconds to see if you can do that.

If you'd like a little bit more time to read all the properties, feel free to pause the video now and then restart it when you're ready.

Okay, so looking at the different properties, let's read the first one.

It says has six square faces.

Now the key word in this is the word square.

Because the only shape that has six square faces is a cube.

So I'm going to write A here because it's a cube.

And a cube has all of its faces that they're exactly equal.

All of the edges have the same length, and all of the faces are square rather than rectangular.

If they were rectangular, we would call that shape a cuboid.

Next one says it has five faces.

Which of those shapes has five faces? Well, you should have seen that it was shape C, it's a triangular prism.

Three of the faces are rectangular, and two of the faces are triangular.

So you've got a five faced prism there.

The third property is, has one curved face and two flat faces.

Has one curved face, and two flat faces.

Well, there are two shapes on here that have a curved face, but only one of them has two flat faces.

And that is shape E it's a cylinder.

So you've got the curved face that goes all the way around the outside of the shape.

And then the two flat faces one at the top and one at the bottom, both of which are circular.

And the last one has one curved and one flat face.

While the other shape that has a curved face is the cone.

But it also has a flat face, which is the base.

And that is a circular face as well.

So the only shape there that we didn't use was our tetrahedron, our triangular base pyramid.

And let's look at some vocabulary.

So we've been learning about this vocabularies as we've been going through our 3D shape unit.

So we've got different words here on the left, we've got the word face, your turn to say it.

My turn, edge, vertex, vertices, and apex.

I'd like you to spend a couple of seconds now and pause the video, feel free to pause the video if you would like a little bit of extra time, to have a couple of seconds to see whether you can match each of those names, and each of those terms, to one of the definitions on the right hand side there.

Have a couple of seconds to see if you can make your match.

Okay, let's have a look together.

So the first one says a face.

Now a face of a 3D shape, is a flat or curved surface on a 3D shape.

So you might find that for example, on a shape like a cube or a cuboid, all of the faces are flat faces.

And whereas on something like a cylinder, you have a combination of flat and curved faces.

Flat and curved surfaces on a 3D shape.

Now an edge is the area where two faces meet.

So when you get two faces that meet together on a 3D shape, we call that an edge.

It's used to describe the space where two faces meet on a 3D shape.

We don't typically use the word edge when we're talking about 2D shapes, we use the word side instead.

A vertex is a corner where the edges meet.

And vertices are corners.

It's the plural version of vertex.

If you have just one corner you'd call it a vertex.

If you have several, you call them vertices.

And the apex is the corner having all the vertex at the very top of the shape.

And it is usually located opposite the base.

Not all shapes have apexes.

So if you think about a cube, it does not have a distinctive top corner.

And whereas something like a cone does, it has an apex right at the very top, and that is opposite the base.

So not all shapes have apexes, but some of them do.

So now let's use some of the terminology that we've identified, to describe different 3D shapes.

Have a look at the 3D shape on the left hand side of your screen.

I wonder whether you can spend a bit of time having a look to see whether you can identify how many faces, edges and vertices the shape has.

And also, whether it has an apex or whether it doesn't have an apex.

I'm going to give you 10 seconds to identify that information.

So let's have a look together.

First of all, we're going to identify the number of faces.

I'm going to count them as we go.

And I'll draw around them so we can see which ones we've already counted.

So we'll start with this triangular face here.

We've got one here.

And then we've got another one here, that's two.

We've got one going towards back here, three.

One right at the back here, which is four.

And one here, five.

And then one here, six.

And then we've got, we can't forget the base, which is also a face that's seven faces.

So this shape has seven faces, including its base.

Now let's think about the number of edges.

So if I rub out all of my markings, then what I can do is show you the number of edges.

This time, let's use a slightly different colour so we can identify the edges.

So in blue, let's have a look.

Remember an edge is any space where two faces meet.

So we've got one, two, three, four, five, six, seven, eight, nine, 10, 11, we've got 12 just here.

So this shape has 12 edges.

So now let's look at the number of vertices that this shape has.

So I've hanged my pen colour again, it's now a pink.

Let's have a look at those corners, those vertices on this shape.

So let's start here.

I've got one.

Two.

Three.

We're going all the way around the base first.

Four, five, six, and then we've got the apex up here, which is seven.

So we have seven vertices.

And we do have an apex.

One of those vertices is an apex, it's that very top point.

So there we've identified the number of faces, the number of edges and the number of vertices that this shape has.

So now it's your turn to have a go.

I'd like you to have a look at this shape that we have on the screen here.

This shape is called a hexagonal prism because it makes use of two faces, which are hexagons.

Hexagons are six sided shapes.

I'd like you to see whether you can use the same vocabulary that we used previously to describe this shape.

I want to know the number of faces, the number of edges, the number of vertices and whether there is an apex or not.

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

Let's have a look together and see what we can identify in terms of the properties of this shape.

So let's start with the number of faces this shape has.

Once again I'm going to draw them on.

So I'm starting over here.

I've got this face here, which is one.

Then I've got this face here, which is two.

I've got another face here, which is three.

This one is four, five, and this one here is six.

Then we've got one at the top and one at the bottom there.

So there are eight faces.

Six of those faces are rectangles, and two of those faces are hexagons.

Now let's look at the number of edges that this shape has remembering the edges, is the area where two faces meet.

So using a slightly different colour pen, let's have a look at the number of edges.

We've got one.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

Nine.

10.

11.

12.

13.

14.

15.

16.

17.

18.

So we have got 18 edges there.

You can see why drawing the edges on is so useful, because it allows us to see exactly what we have covered and what we haven't covered.

So now using a pink, let's see whether we can identify the vertices.

Remember vertices are the corners, where those different edges meet.

So start at the top, one.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

Nine.

10.

11.

12.

And you might have noticed something really interesting, which is that as we're dealing with hexagons, and we've got two hexagons here, we know that hexagons have six sides.

And so in terms of the number of vertices, we're doubling that number to identify that there are 12 vertices on this shape.

So all of the six sides of our hexagons have been attached to edges which create vertices.

And in this case there is no apex on this shape, because there is no distinctive top vertex.

Moving our learning on a little bit, let's have a look at constructing 3D shapes now.

There's something that might be really useful for the first part of the lesson, is some building blocks, Lego, deans, any kind of blocks that you have at home if you have them.

If you don't, don't worry, you can do this all visually if you're able to.

And but if you do have anything that you can stack up even if they are cereal boxes, anything that is kind of a box shape, or a cube or a cuboid shape is really useful to help you identify the properties of these 3D shapes.

So you can see here we've used deans to construct three different shapes.

The first one is what I would describe a cube, as we've seen before quite often.

The second one, is an elongated version of the cube and you can see that it is a cuboid.

And the reason we call this a cuboid not a cube, is that it makes use of rectangular faces as well as square faces.

So with a cube all of the faces are squares, whereas with a cuboid, the faces can be a combination of squares and rectangles, or just rectangles.

And the final third shape is a bit of a irregular shape.

And we wouldn't normally have a specific name for it, but it's been made out of 3D cubes stacked together.

So if you have cubes or boxes or anything at home that you can use to replicate these blue deans cubes, spend a bit of time now constructing these three shapes in front of you, 'cause it will help you identify their properties.

Pause the video now to construct those shapes if you have those materials at home.

So now what we can do is we can start having a look at the properties of these shapes, and see how the properties of these shapes change as we extend them.

Let's first look at the cube.

Can we identify the different properties of the cube? Let's first look at the number of faces the cube has.

We know that it's got four faces going around the edge of the cube and then one at the top and one at the bottom.

And therefore it has six faces.

Now, can you identify how many edges this shape has? I'm going to give you five seconds to have a think how many edges do you think a cube has? Okay, let's count them.

Let's have a look.

So I'm going to highlight them as I go.

I've got one, two, three, four, five, six, seven eight, nine, those are the visible ones.

Now let's look at the ones at the back.

10.

11.

12.

The one in the back, 12 edges.

And now let's look at the vertices those corners.

Again, I'm going to count them as I go.

One.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

We have got eight vertices with no clear apex there at all.

So six faces, 12 edges and eight vertices.

And interestingly, we know that square is a four sided shape.

The number of vertices is double that it's almost like we're creating a prism with that cube.

Now looking at the cuboid.

Can you identify how or if any of those properties from the cube will be different for the cuboid? I'm going to give you five seconds.

What do you think the properties of the cuboid will be? Okay, let's have a look together.

So first of all thinking about the number of faces.

Remember that even though we've got two blocks here together, that still counts as one face.

This is all still one face, because we haven't separated out those cubes, they're still one face.

So how many faces does the cuboid have? Well, it has exactly the same as the cube, we've still got six faces.

We've still got 12 edges.

And we've still got eight vertices.

So you can see here, that actually even though the cuboid is a different shape, it has the same properties, because it's still just an elongated version of the cube.

So now that we've identified the properties of the cube and the cuboid, let's have a look at these irregular shapes.

So we've already seen the shape as the shape number one, this is the irregular shape that we saw earlier.

And this is shape number two, this is another irregular shape.

Let's have a look at shape one together.

First of all, let's think about the number of faces that shape one has.

So first of all thinking about the fact that I can see this face here, this is a visible face, this is one.

And this exact face would be on the reverse side, that would make two.

I've got another face here, which is three, a face underneath, which is four.

This side face, which is five.

This top face, which is six.

This face along here, which is seven, and the base face, which is eight.

So this shape has eight faces.

Now let's think about the number of edges this shape has.

This is a little bit more challenging, because we have to imagine what's on the other side.

If you've constructed the shape, with cubes at home, this will help you out a lot.

Let's have a look at the number of edges.

So I'm going to start by counting the edges here.

One.

Two.

Three.

Four.

Five.

Six.

Now because I know that there are six edges on this side, there's got to be six edges on the other side.

Therefore, there are 12 edges on the front and the reverse sides.

Now I'm going to count the horizontal lines.

So the horizontal edges, so I'm starting with 12.

13 along here.

14 for the little edge that goes along there that we can't see.

15 here.

16.

17.

And then there'll be one here that run on the back, that connects up to the back of the shape.

That's 18 edges.

And now thinking about the vertices, the vertices we can see and the vertices we can't see.

We've got one.

two.

three.

four.

five.

six.

Again, another six on the other side, therefore, we've got 12 vertices overall.

So you can see that even though we can't necessarily see, all of the different parts of the shape, using our imagination, using our understanding of 3D shapes we can imagine, the different edges faces and vertices on the shape.

So what I'd like you to do now is do exactly the same thing for shape two.

As I said, if you've got any cubes, Lego, blocks, cereal boxes, chocolate boxes, anything at home that you can use to construct this shape, that will be really helpful to help you out with constructing the shape and identifying the number of faces, edges and vertices that it has.

If not have a go using your understanding of what the shape would look like from the front and from the back.

Pause the video now to complete this and resume it once you're finished.

Okay, let's have a look at it together.

So let's see, first of all, how many faces this shape is likely to have.

So we can see here that we're starting with the front.

So this is the front face here, which is kind of almost like a Z shape.

That's face number one.

We've got exactly the same face on the back.

So that'll be shaped face number two.

A face right at the base here, three.

This face here four.

Five.

Six.

Seven.

Eight.

Nine.

10.

This shape has 10 faces.

And we can imagine where they all are based on what we can see and also what we can't see.

So we can also use our imagination to imagine where the other faces on this shape are.

Now thinking about the number of edges on this shape.

So again, we're looking at those straight lines to help us out with this.

I'll start from here, so one.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

Exactly the same number on the other side.

So there'll eight on the other side too that brings us up to a total of 16.

Then we've got 17 here our horizontal lines 18 19 20 21 22 23.

And then we've got our 24th one there it goes around the back here.

There are 24 edges for this particular shape.

There are lots more edges in this case.

And finally, let's look at the number of vertices that we have.

So we're looking at those corner points.

One.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

And exactly same on the back.

So we therefore double it.

So we've got 16 vertices.

So quite a challenge there, to identify the number of faces, vertices and edges on irregular shapes.

But you can see some patterns start to emerge if you can identify the number of vertices or the number of faces on one side, it helps you identify the same number for the other side as well.

So let's apply this to even more irregular shapes.

Have a look at this shape just here in front of you.

You can see, that it's made up of different blocks which you can create at home if you've got some Lego bricks, or if you've got some boxes at home, it might be really useful to try and create this shape.

I would like us to have a think about how we're going to identify the properties of this constructed shape.

So just like we did before, we're going to identify the number of faces, the number of edges, and the number of vertices on the shape.

If you'd like to, pause this video now to construct this shape at home, have a go yourself and then restart it when you want to go through it together.

We're going to go through it.

We're using this pictorial demonstration or this pictorial shape just in the screen here.

So let's start, by looking at the number of faces its shape has.

Well I'm starting with the largest face, which is this very top one here.

So all of this that I'm outlining in pink here is one face, and we know that if we've got that face on the top, we've got the same face on the bottom, so that's two overall.

Now let's look at the sides.

We've got three.

Four.

Five.

Six.

And now besides that we can't see.

Seven.

Eight.

Nine.

10.

10 faces overall on this shape.

Now let's think about the number of edges.

So if I rub out my markings, we can see them a little bit more clearly reminding ourselves that the edges, are the areas where those two faces meet, or two or more faces meet.

So looking at the number of edges.

Let's start with the very top outline.

One.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

And we must have exactly the same below.

So we've got a 16 therefore.

And now I'm going for the straight edges, or the vertical edges sorry.

17, 18, 19, 20, 21, 22, 23, and 24.

So we've got 24 edges.

And then looking at the vertices where I'm going to count the top vertices first.

One.

Two.

Three.

Four.

Five.

Six.

Seven.

Eight.

Same number of vertices on the lower side as well.

So therefore, there are 16 vertices on this shape in total.

So you can see here a systematic approach is really important if you're using the pictorial method to calculate the faces, vertices and edges.

Try and make sure you're going through in order.

Start with all the horizontal edges for example first, and then look at the vertical edges, rather than trying to do it randomly 'cause you'll lose track of where you are.

This is your independent task for today.

I'd like you to choose, or actually for all of these shapes, the red, orange, blue, yellow, and green shape, I'd like you to write one sentence to describe its properties.

Try and use the vocabulary that you can see on the screen, faces, edges and vertices.

You might also like to refer to how many blocks have been used to make up each shape.

So for example, for the yellow shape there, we can see that in terms of the number of blocks that have been used, we've got one.

Two.

Three.

Four.

Five.

Six.

Can you identify how many blocks have been used for each of the shapes? Try and see whether you can use or identify, the number of faces edges and vertices for all of those five shapes.

You may find that if you've got Lego, or blocks, or deans at home that you can use to construct these shapes, that would be very, very helpful to help you identify the different properties of each of the shapes.

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

Oh, it's been really great having you join the lesson today.

I know that what we've been tackling, it's actually been really challenging looking at 3D shapes and constructed 3D shapes and thinking about their properties.

I'd love to see the work that you've been doing and I'd love to read the sentences you've written about the shapes that we've been looking at today.

So if you'd like to please ask your parent or carer to share your work on Twitter, tagging @OakNational and #LearnwithOak.

Now it's time to complete your quiz.

Thank you so much for joining us for our maths lesson today.

It's been really great to have you.

Do join us again soon.

Bye bye.