Lesson video

Hello everybody, my name is Mrs. Johnson.

I am really happy to be here today to help you with some of your maths learning.

I hope you are ready to work hard and have lots of fun.

Let's see what we are going to be learning about today.

This lesson is called Discuss and Compare Polygons.

It comes from the unit Shape, discuss and compare 2D and 3D shapes.

By the end of this lesson, you will be able to discuss and compare the shape and size of polygons and the vertices of polygons.

You're going to be thinking about looking at different polygons and saying what might be the same and what might be different about them.

Make sure that you are ready to be looking carefully at lots of different polygons today.

There are three key words that we are going to practise to get you ready for your learning in this lesson.

I will say them first and then it will be your turn, ready? My turn, larger, your turn.

My turn, smaller, your turn.

My turn, compare, your turn.

Well done, listen carefully for those words throughout this lesson, because they are going to be really important to your learning today.

There are going to be two parts to this lesson.

To begin with, you are going to learn about comparing size and shape, and then in a little while you are going to learn about comparing vertices.

Let's start with comparing size and shape.

There are two friends who are going to help us in this lesson, their names are Aisha and Izzy.

Listen carefully to the things that Aisha and Izzy have to tell you, because they are going to be really helpful today.

Look carefully at these two shapes.

What is the same about them and what is different? I wonder if you notice anything that you can see that might be the same or that might be different.

Aisha has noticed some things that are the same.

Let's see if Aisha's ideas are the same as the things that you might have noticed.

Aisha says they are both polygons.

They both have one vertex at the top, in the middle just here.

Aisha says, "They both have three vertices at the bottom." Aisha's noticed quite a few things that are the same, I wonder if you noticed anything else.

I wonder if there's anything that's different.

Izzy has noticed some things that are different.

Let's see if you notice these things too.

Izzy says, "A has six sides and B has four sides." They have a different number of sides.

Izzy says that A has six vertices and B has four vertices.

You can count the vertices and find that these shapes have a different number of vertices.

B is wider than A at the bottom, but narrower than A at the top.

Have a look at these arrows to see what Izzy means, at the bottom of the shapes, B is wider, but at the top of the shapes, B is narrower.

Izzy has noticed quite a few things that are different about these shapes, I wonder if you thought about anything else that might be different about these two shapes.

When you look at what is the same and what is different about two or more shapes, you are comparing them.

Izzy says, "I can compare these two rectangles." I wonder what she's going to notice about these two rectangles.

Let's have a look.

Izzy could say that A is taller than B.

Izzy could say that B is wider than A.

She could say that A is larger than B, because it takes up more space.

Izzy says, "If these were slices of cake, I would choose A because I would get more." Oh, that's making me a little bit hungry thinking about cake.

Can you see why if you love cake, you would want to choose A and not B, wouldn't you? Because if you choose A, you would be getting more, A is larger than B.

Who do you think has compared these shapes correctly? Look carefully at A and B.

Izzy says, "I think A looks narrower than B." Aisha says, "I think A looks larger than B." Andeep says, "I think A looks taller than B." Who do you think is correct? Pause the video and have a think.

Let's have a think about what each person has said.

Izzy said, "I think A looks narrower than B." That's not right, is it? Izzy could say that A is wider than B or B is narrower than A, but you can't say that A looks narrower than B, that's not right.

Aisha said, "I think A looks larger than B." She is correct, isn't she? If you look carefully at those two shapes, A takes up more space than B, so that means that A is larger.

Andeep said, "I think A looks taller than B." If you look carefully at those shapes, you could actually say that A and B are the same height, but neither one is taller than the other, so Andeep was not correct.

The person who did compare the shapes correctly was Aisha.

Izzy and Aisha have drawn some slices of pizza for Pedro.

Let's imagine that Pedro is feeling really hungry.

Which slice of pizza should Izzy and Aisha give him? Aisha is thinking about this slice of pizza.

She's noticed that this slice looks longer than all the others, but she's also noticed that it's very thin, so Aisha says that this is not the largest slice of pizza.

I wonder which one it could be.

Izzy is thinking about this slice of pizza.

She says, "I think that this piece looks much wider than all the others, it takes up more space, so this is the largest slice of pizza." This is the slice of pizza that they should choose to give to Pedro.

There we go, Pedro is going to have that slice of pizza, he is so hungry, he needs the largest slice of pizza, so this is the slice of pizza that he needs to have.

Izzy and Aisha have drawn some slices of cake for Pedro too.

Pedro is feeling quite full now, remember, he ate the largest slice of pizza, so he hasn't got much room left in his tummy, he is quite full, he only wants a small piece of cake.

Which piece of cake should Izzy and Aisha choose to give to Pedro this time? Aisha's thinking about this slice of cake, and she says, "This one looks shorter than all the others, but it is quite wide, so this is not going to be the smallest piece of cake." I wonder which one it could be.

Izzy is thinking about this slice of cake.

She says that, "This slice looks much thinner than all of the others, it takes up less space, so this is the smallest slice of cake." Let's give the smallest slice of cake to Pedro.

He only wants a little bit this time, so he'll be happy with the smallest piece.

Let's check if you can say which shape is the largest or the smallest.

Here are three different rectangles.

Which rectangle do you think is the largest and how do you know? Pause the video and have a go at that now.

If you look carefully at all three rectangles, you will notice that you could say B is the longest rectangle, but it's long and thin, so it doesn't take up the most space, it is the longest, but it is not the largest.

You could say that C is a bit wider than A.

If you look at these arrows, you can see, can't you, that C is wider than A, but A is longer than C.

A takes up the most space out of all of these rectangles, that means that A is the largest rectangle.

It is not the longest rectangle and it is not the widest rectangle, but it does take up the most space, so it is the largest rectangle out of these three.

Well done if you said A.

Now it's time for you to practise comparing size and shape.

For question one, you are going to talk about these questions with a partner.

Have a look at all of the shapes that you can see here.

First, talk about what is similar about all of these shapes.

Then talk about which shape do you think is the largest, and which shape do you think is the smallest, and most importantly, how do you know which one is the largest and which one is the smallest? When you have finished that, you are going to choose two shapes from the shapes that you can see here.

You are going to make a list of all the things you can see that are the same and all the things you can see that are different about those two shapes.

Pause the video and have a go at that now, off you go.

Let's have a look at what you might have said when you were talking to your partner about these questions.

Aisha said, "I noticed that all of these shapes are polygons, because all their sides are straight." That's something she noticed that is similar or the same about all of these shapes, they are all polygons.

You could have said that they all have straight sides.

You might have talked about the number of sides too.

You needed to talk about which shape you thought was the largest and which shape you thought was the smallest and how you know.

This is what Izzy said, "I think E is the largest, because it looks like it takes up the most space.

I think G is the smallest shape, because it looks like it takes up the least amount of space." Well done if you talked to your partner about which shapes look like they take up more space or less space, that is how you can decide which shape is the largest and which shape is the smallest.

Now let's have a look at the second question.

You needed to choose two shapes and say what was the same and what was different.

I'm going to choose shape F and shape G.

You might have chosen different shapes, and that's okay.

Maybe we still might have written some of the same things in our list of what is the same and what is different, let's have a look.

I've said that for things that are the same, F and G both have six sides.

They are both hexagons.

They both have two longer sides and four shorter sides.

They are the same shape.

G looks like a smaller version of F.

Those are all the things I noticed that were the same.

I wonder what you noticed about your two shapes.

Now for the things that were different.

I noticed that F is larger than G.

I said that G is smaller than F.

I said that the shapes are facing in different directions, like one of them has been rotated.

Well done if you looked really carefully at your two shapes and you noticed lots of things that were the same and different, that means that you can compare shapes.

Well done, good work.

Now it's time to have a look at the second part of our lesson.

Now you are going to learn about comparing vertices.

We know that when you compare shapes, you can look at the space that each shape takes up, this helps you to say which shape is larger and which shape is smaller.

Aisha says, "I wonder if there are any other properties we could look at when we compare shapes." Izzy says, "I think we could look at the vertices.

We could count them and we could look at the size and shape of them too." We have looked at the size and shape of the whole shape before, but we haven't looked at the size and shape of the vertices yet.

Let's see what that's going to look like.

Let's count the vertices of each shape first.

1, 2, 3, 4, 5.

1, 2, 3, 4, 5.

1, 2, 3, 4, 5.

If we count the vertices, we find that each shape has five vertices.

That means that all of these shapes are pentagon's, doesn't it? A pentagon has five vertices.

That's something that's the same about all of these shapes.

Do you think you noticed anything different about them? Look carefully at the vertices.

Izzy says, "I notice that the vertices look quite different on each pentagon." Do you agree with Izzy? Do you think that the vertices look quite different on these pentagons? Let's have a look in a little bit more detail.

What do you notice about any of these vertices? Do any of them stand out to you for looking a bit different? Aisha notices this vertex, because she says that this vertex looks sharp and pointy.

Izzy notices this vertex, Izzy said, "I noticed that this vertex is a square corner.

It looks like the vertices that you see in a rectangle." This shape is a pentagon, but that vertex does look like the same vertices that you would see in a rectangle, doesn't it? So these vertices look quite different to each other.

Which vertices could Aisha and Izzy be describing here? Let's check if you can match their description to the vertices.

The descriptions are the same as last time, aren't they? But the shapes they are looking at have changed.

Can you see which vertices on these new shapes could they be talking about? Pause the video and have a go at that now.

Izzy was talking about square corners, wasn't she? The shape that has square corners is the one in the middle, and it actually has two square corners.

There is one at the top and there is one at the bottom.

There are two square corners in this shape.

Aisha was talking about a vertex that was sharp and pointy.

She could have been talking about this one, this one looks very sharp, or she could have been talking about this one.

I think both of those vertices look quite sharp and pointy, don't they? Well done if you could match the descriptions to the vertices in those shapes.

Some vertices can be described as sharp and pointy.

This one is sharp and pointy, isn't it? How could you describe the vertices that are the opposite of this? Look at the vertex that this arrow is pointing to, that isn't sharp and pointy, is it? How might you describe that vertex? Aisha says, "I would say this is a wide vertex." Izzy says, "I would say this is a large vertex." Do you agree with Aisha or with Izzy, or do you have your own way of describing a vertex like this? Izzy has thought of another way to compare the vertices of different shapes.

She says, "I noticed that on one of these shapes, all the vertices look the same size." I wonder which shape she's noticed.

Which shape has all the vertices that look the same size? It's this one, isn't it? All of those vertices look the same.

Izzy has noticed on another shape, some of the vertices look same, but some of them look different.

Which shape could she be talking about this time? Let's have a look.

It's this shape at the bottom, these two vertices look the same, don't they? But then these two vertices are different to the first two.

They are the same as each other, but they are not the same as the first two.

That means that this shape has some vertices that are the same as each other, but others that are different.

Izzy has noticed that on the last shape it doesn't seem to have any vertices that are the same, so this vertex looks different to this one and then this one looks different again, and this one looks different again.

None of the vertices are the same, they are all different.

Which words would you choose to describe these vertices? First, this one, then this one, and then this one.

How would you choose to describe these vertices? Pause the video and have a go.

Let's have a look at some of the ways that you could have described these vertices.

You might say that the first one looks sharp and pointy.

You could say that the next one looks wide or large, and you could say that the last one looks like a square corner or it looks the same as the vertices that you would find in a square or a rectangle.

Well done if you thought carefully about how you would choose to describe those vertices.

Now it's time for you to do a bit more practise.

You are going to look really carefully at the vertices on all of these pentagons and talk about these questions with a partner.

Which do you think is the sharpest vertex? Which do you think is the widest vertex? Are there any pentagons with square corners? Are there any pentagons where all the vertices are the same? Are there any pentagons where all the vertices are different? Look really carefully at the vertices on all of those shapes and talk to your partner about all of those questions.

When you have finished that, you are going to have a go at the second question.

You need to draw a quadrilateral and check once you've drawn it that it has four vertices.

Choose one of the vertices and write a sentence to describe it.

Perhaps you could draw an arrow pointing to the vertex that you've chosen.

Then draw a different quadrilateral in the second box and have another go at describing one of its vertices.

Pause the video and go and have a go at that now.

You looked really carefully at all of these pentagons to have a go at these questions.

This is what you might have said to your partner.

Which one do you think is the sharpest vertex? You might have chosen this one, it looks really sharp and pointy, doesn't it? You maybe even said that it looks more pointy than all of the others, it's the sharpest vertex.

On the second question, which do you think is the widest vertex? You could have chosen this one.

Maybe you said this one is the widest vertex because it looks like a three-quarter turn.

The next question was, are there any pentagons with square corners? You and your partner might have talked about these two vertices here, these are both square corners.

You might have also noticed there is another pentagon with square corners.

These two vertices here are square corners in this pentagon.

Well done if you noticed those.

The next question was about any pentagons where all the vertices are the same.

There is one pentagon that has all its vertices the same, it's this one here, well done.

You could have said, I think all five vertices in this pentagon are the same size.

Finally, you needed to see if you could spot any pentagons where all the vertices are different.

You and your partner might have talked about this one.

Maybe you said, I think all the vertices in this pentagon look different sizes.

You had to look and do lots of thinking about the vertices in these pentagons, so well done for looking so carefully, good job.

On the second question, this is how you might have drawn your quadrilaterals.

Maybe you drew something a bit like this, or maybe you drew something like this.

Did you make sure that your quadrilateral had four straight sides? That's really important for a quadrilateral, isn't it? You could describe the vertices you chose like this.

I chose this one for my first quadrilateral.

And I said, this vertex is a square corner, it looks like the vertices you see in a rectangle.

On my second quadrilateral, I chose this vertex and I said, this vertex is very pointy.

If I touched it, I imagine it would feel sharp on my finger.

Did you think about the vertices that you chose and how you could describe them? Maybe you chose a sharp, pointy vertex.

Maybe you chose a really wide or a large vertex, or maybe you chose a square corner like I did.

Well done for thinking carefully about how you could describe those vertices.

Now that you are at the end of the lesson, you have learned that you can compare shapes by looking carefully at what is the same and what is different.

You can look at the properties of a shape, things like the sides or the vertices to help you compare them.

You can look at how much space a shape takes up to be able to compare shapes and say which is larger and which is smaller.

If you had these two shapes, A and B, you now know that you would be able to say, A and B both have five sides, B has some sharp vertices, and A has some square corners.

Well done for all your hard work today, you have learned lots about being able to discuss and compare polygons, excellent work.

I hope that I'll see you again soon for some more maths learning, bye everybody.