Lesson video

Hi, everyone, I'm Miss Miles and welcome to your maths lesson.

Before we start, a did you know fact.

Today's fact is, did you know that the only even prime number is two? I wonder if you can have a think about why that might be.

Okay, back to today's lesson.

For today's lesson you will need a pencil, a piece of paper and a clear workspace.

In today's lesson, we will be identifying, comparing and classifying shapes, based on their properties.

Now, we're going to start by having a look at a video of a triangular prism, looking at the properties and everything there is to know about it.

So, when you're ready, let's watch it together.

Okay, so, I've got my triangular prism here, I'm going to count the faces first.

So, I have one, two triangular faces and one, two, three rectangular faces, five faces in total and one, two, three, four, five, six vertices.

Now, let's look at the angles.

So, at vertex one, there's one, two, three angles, at vertex two, there's one, two, three angles, and at vertex three, there's one, two, three angles.

Vertex four has one, two, three angles, vertex five has one, two, three angles and vertex six has one, two, three angles.

Six lots of three, 18 angles in total.

Now, let's measure them really carefully using a protractor, I'm going to use the inner scale on these angles because they are acute, they are less than 90.

I'm lining it up and I can see that my first angle in my triangular face is 60 degrees.

Let's have a look at the next angle now, I'm lining it up really carefully and making adjustments where I need to, to make it as accurate as possible, and that one is also 60 degrees.

The final angle in my triangular face is also, when I've measured it really carefully, 60 degrees.

So, there are three 60 degree angles on each triangular face.

Rectangular faces now, we can measure our angle at 90 degrees.

And in total there is one, two, three rectangular faces.

So, on each rectangular face, there are four angles and they are all 90 degrees each, so three lots of four make 12.

12 angles at 90 degrees and six angles at 60 degrees.

Now, that's all there is to know about a triangular prism, so I'm now going to use all of that knowledge to help me draw a 3D representation of that shape.

On screen now, there are some steps to show you how to draw a 3D shape.

Now, I know that this shape is a prism, it has an identical face at each end, so I start by drawing those two faces, as you can see on screen, two triangular faces.

Then I connect a vertex on each, then I connect the rest of the vertices together and that gives me my finished triangular prism.

I've created a video of me following these steps to show you and then you're going to have a go.

So, let's watch the video together.

Okay, so I'm going to start by drawing my first triangular face, now I'm going to try really carefully to draw up my second triangular face and look, I'm sketching it, so I'm really making sure that they are similar as they can possibly be.

Now, I'm going to join the vertices together, so vertex one on each triangle and I'm going to join them together with as straight a line as I possibly can.

Now, vertex two, I'm going to join that together with a straight line and finally vertex three on each triangle, I am going to connect together, giving me a triangular prism.

Now, as you can see, I sketched mine just using a pencil and a piece of paper and you can do the same as me.

If you do have a ruler or squared or dotted paper, you can use that if you want to, to make your drawing more accurate, but if you don't, it's fine, sketch it just like I have.

Have a go at that for me, pause your video there.

Okay, how did you get on? We're now going to have a go at drawing a cuboid, similar in the fact that it is a prism but instead of having a triangular face at each end, I have a rectangular face at each end or sometimes a square.

So, I'm going to start in a similar way, by drawing two squares and then joining them together at the vertices.

So, let's watch that video together now.

So, I draw rectangle one or square one, as carefully as I can, I'm sketching it out again.

Now, number two, again, trying really hard to make them as similar as I possibly can, sketching.

There we go, now to join the vertices.

So, vertex one, I join them as straight as I possibly can.

Vertex two, I'm going to join those together now.

Now, vertex three and finally, vertex four.

And there we have our cuboid.

So, pause your video there and have a go at drawing a cuboid for me.

Okay, how did you get on? Hopefully, you've now drawn two really good 3D shapes.

So, independent task time now.

Task one, you are going to use the images on screen to help you sketch some different 3D shapes.

Now, if you think back to when I drew my triangular prism, before I got started on drawing my shape, I had to really carefully consider everything I knew about it first because using that knowledge helped me to draw the best shape I possibly could.

So, you need to pick a shape for me, identify the properties that you know about that shape and then use that to help you draw a representation of it for me.

So, choose as many as you like, pause the video there.

How did you get on with that? Hopefully, you really enjoyed it.

Now, independent task two.

Now, this one's a bit of an investigation for you.

How many different cuboids can you draw? They might be tall, they might be short, they might be wide, it's up to you.

How many can you draw? Investigate for me, pause your video there.

Okay, how many cuboids did you manage to draw? I bet you managed to draw lots.

Well done for completing today's lesson.

Don't forget the end of lesson quiz and hopefully I'll see you again really soon.