Lesson video

Hi everyone.

How are you today? I'm Ms. Mitchell.

And today in maths, we're going to be identifying shapes by the number of vertices and sides.

In today's lesson, we will be identifying shapes, you will then complete a worksheet and then a quiz.

For today's lesson.

, you will need a pencil, a ruler, and some paper.

If you have not got this ready, please pause the video now to get this.

I need your help.

So a mysterious shape has stolen this poor boy's pencil case.

So we need to work out who done it.

Now, the teacher has told us that the thief has more than three sides.

So just have a little think about what shape we know that it is not.

And we know that the shape has more than three sides.

Now, somebody else has told us that they are sure he had less than five sides.

The shape has less than five sides.

Can you now pause the video and have a think about what shapes it could be.

What shapes is it not? When we know it has more than three sides and we know it's got less than five sides.

So pause the video now and have a think, look on this screen about what shapes the culprit could be.

Well done.

So this shape here is called a rectangle.

Now, could it be the shape here? Does it have more than three sides? Yes.

Does it have less than five sides? Yes.

So it could be the shape here.

This shape pair has five sides, which is called a pentagon.

Can you say pentagon? Fantastic.

So could it be this shape? No.

Straight away we know that it can't be this shape because it has five sides or more, and we know it's got more than five sides.

What shape is this? It is a triangle.

A triangle has three sides.

Could it be the shape? No, it can't be because we know it has more than three sides.

Here, we have another triangle.

So could it be this shape here? No.

'Cause we already know that it has more than three sides.

What shape is this? This is a parallelogram.

Can you say parallelogram? Parallelogram.

Parallelogram.

It's a tricky word to say.

Isn't it? Could it be this shape here? Has it got more than three sides? Yes.

How's it got less than five sides? Yes.

So it could be this shape here.

Well done.

Here, we have another shape.

Now, it has four sides and they are all the same length.

So what is this shape? It is a square.

Could it be the shape over here? Yes, it could.

Because again, more than three sides, less than five sides.

What about this shape over here? This has one, two, three, four, five, six sides.

What shape has six sides? That's right.

A hexagon.

Can you say hexagon? Hexagon.

Could it be the shape here? Straight away, we know it can't be because it has more than five sides.

And we have two shapes over here that both have four sides.

Could these shapes be the culprits? Yes they could, because it has more than three sides and less than five sides.

And this shape here is called a trapezium.

Can you say trapezium? Trapezium.

Lovely.

And this shape here is called a rhombus.

Can you say rhombus? Rhombus.

Well done.

Now, here are some different shapes.

Can you pause the video and have a think? What is the same about them? What is the same about these four shapes? That's right.

They all have four sides.

One, two, three, four.

One, two, three, four.

One, two, three, four, and so on, and they also all have four vertices.

A vertex is a corner.

So one, two, three, four.

One, two, three, four, and so on.

So all these shapes have four sides and four vertices.

Now, can you have a little think about what is different about them? What is different about these shapes? That's right.

All their sides are different lengths.

Now, I'm going to introduce you to a word you may know it already, you may not, and the word is quadrilateral.

Now, a quadrilateral refers to flat shapes, so 2-D shapes that have four straight sides.

So any shape with four straight sides is called a quadrilateral.

Can you say quadrilateral? One more time, quadrilateral.

Fantastic.

Now, here is a shape.

Can you please tell me whether or not this shape is a quadrilateral? Does it have four flat sides? One, two, three, four, five, six, seven.

The shape has seven sides, which means it is not a quadrilateral.

It is in fact, a heptagon.

Here is a different shape.

Is this shape a quadrilateral? No, it is not.

And why is it not a quadrilateral? That's right, because it doesn't have four straight sides.

It only has three sides, which makes it a triangle.

Now, with this shape a quadrilateral? Yes it is.

And why is it a quadrilateral? That's right, because it has one, two, three, four sides, four straight sides.

Is this shape quadrilateral? No.

It is not.

It is a triangle.

And why is it a triangle? Because it has one, two, three sides.

It doesn't have four sides.

So for your task today, I would like you to draw different quadrilateral.

I would like you to explore the different lengths of sides that are possible.

So you are drawing four-sided shapes, four straight sides.

And pause the video now to do this.

And pause the video now.

Press play when you are ready for the quiz.

There will be no answers today as everyone's drawings will look different.

If you'd like to share your work with Oak National, please ask your parent or carer to share your work on Twitter tagging @OakNational and #LearnwithOak.

Fantastic work today.

Now, let's see what you can remember by completing the quiz.

Well done.