Lesson video

You're going to need, as usual, all the equipment listed.

Your pencil, your ruler, important.

Something to work in or on and somewhere quiet with no distractions.

So try and forget the chicken, the amazingness of your mind reading talents.

Now let's see, just if you can focus on our work.

So knowledge, cause we've done.

Check mark that one off.

We've done our best to do our key learning of vocabulary.

Then we're going to move on to some number sequences.

We're going to recap on triangles and then focusing on scalene and isosceles triangles, main triangles activity, and then a final knowledge quiz to see what you remembered.

So, today we are going to identify and classify, scalene and isosceles triangles and our key vocabulary, my turn your turn.

Triangle, right angle, scalene, isosceles, compare, equal.

Be really careful with those two words or try them again.

Okay.

Scalene, isosceles.

Don't get confused, which one child did once and kept calling it this over and over again.

It's not ice sausages.

Isosceles, okay? So make sure that you're, you're getting that right.

I don't want any sausages today, thank you.

All right.

Starting off with our number sequences.

Remember, we've done this before, and we should stick to the rule for each sequence.

So for example, look at the first one.

It's the same example you've done before, but just check it.

We've got it's going up.

So, it's ascending while we are adding and it's going 25, 30, 35, 40, 45, 50.

The pink ones are the missing ones.

So I can say that I'm adding five every time or I'm increasing by five or whatever these are doing.

That's what you need to tell me.

Remember, increasing or ascending means it's getting bigger, decreasing or descending means it's getting smaller.

Give it a go, come back when you're ready so that I can check on how you did.

Okay.

So here are your answers.

Take a look over them.

The first one, my example, we were adding five and then we were adding two every time.

So, we were increasing by two and a third one down there we were halving.

Okay, and just if you've been halving, make sure you spell it correctly.

It's not half H-A-L-F-I-N-G is a V there, some of those spelling rules, then we're adding four every time, we're subtracting 12 each time, and then in the last time subtracting 0.

2 every time.

And if you remember what I've tend to do before, when it's got decimals, I'll just look at the two bits separately.

So, I'll look at the whole number and I'll look at the decimal separately.

The whole number was staying the same until the end here.

My decimal was going eight, six, four, two, and so on.

That helped me work it out.

So, sometimes just looking at that number in two parts really, well, helps if you kind of partitioned that number, it helps with your sequencing.

So, recap time.

One is a triangle.

Well, remember a triangle is a polygon with three edges, one, two, three, or three sides.

One, two, three.

So edges sides, same thing, but there's two D shapes we tend to say sides more than edges and it has three vertices.

One, two, three.

Vertices are the same as corners or the same as angles.

So, take a look here.

What's the same and what's different.

We're talking about the properties.

The colour of the line is not one of the properties.

That's quite a common mistake.

Actually, people think that the colour is drawn in is one of his properties.

Well, that's not true because if I say the property of a square is that it's blue.

That means that every square we ever see would have to be blue and that's not true.

This is just so we can see the different triangles.

Okay? So, the properties are the sides, the length of the sides, the size of the vertices.

Looking at these ones, are they all the same? What's the same, what's different.

Let's explore.

One of the types of triangles we're looking at today are what we call scalene triangles.

Okay? Now in these triangles, no sides are the same length and no angles or vertices measure the same.

So they're all slightly different.

Okay? And if we look at this one here, we can see that each of those sides are slightly different in length and each of the vertices, the angles are slightly different.

If you stand them up and this is how I remember a scalene triangle.

So, if I were to put it on its base and let's look at the orange one here.

If I put that on its base, it kind of the point at the top leans to one side, scalene, the triangle leans.

That's kind of how I remember.

Okay? It's a sloppy way of remembering, but it works for me.

Moving on.

So, remember scalene triangle, no sides are the same and no angles or vertices measure the same.

This one is an isosceles triangle and then an isosceles triangle, two sides are equal.

So, one, two they're equal.

They're the same.

They're the same and then this one, can you spot the sizes are the same? Yeah, this one and this one.

So, two sides are equal to each other and two of the vertices then are also equal.

So, this one and this one are the same.

This one and this one.

These two and these two.

So, you can't quite see that one, but they're the same as well.

So, two identical sides and two identical vertices, and these ones are called isosceles triangles.

Just say that word for me again.

Isosceles.

Give it a go, but tricky word to say, right? So, have a look here.

You've got one, two, three, four, five, six triangles.

Can you name them? Are they isosceles or are they scalene? Remember the rules we just said, and you'll have to look really carefully.

Which are isosceles? Which are scalene? Give it a go.

Remember my way of remembering a scalene triangle is that if you stand on this base, it kind of leans to one side.

That's not a mathematical way of explaining it.

That's just how I remember it.

Okay? Give it a go.

Which are isosceles? Which are scalene? Name them.

Welcome back.

How was that? Did you manage okay? Did you get the spellings okay? Let's take a look, shall we? So, we've got pink one is isosceles.

The purple is isosceles and I know that because two sides are equal.

Scalene, I'm looking at that and I can't see any matching sides.

Same here.

Here, I've got matching sides.

Not so much here.

Now, in an isosceles don't forget two matching sides means two equal vertices.

Yeah.

Brilliant.

Hopefully, you managed all right with those.

I'm sure you did.

Let's move along.

So, here is your main task and today it's again, it's another day of me talking a little less because I want you to explore.

So, you've got two sets of dotty pages.

Now, on the first set of dotty pages, how many different isosceles triangles can you make on a four by four grid? So, this is four dots going along four dots going down.

It looks like an array.

Doesn't it? How many different isosceles triangles can you create? And by different, it could just be pointing in a different direction.

Okay? Once you've done that, move on and see how many different scalene triangles you can make on the four by four grids.

Okay? Now, let's have a little friendly talk here.

What are you going to do to make sure that these triangles look like triangles? What piece of equipment might you be using to help you get those triangles just right.

I'm saying nothing.

A ruler.

Yeah.

Brilliant.

Sure you will.

And if it's a triangle, you're literally just joining up three points.

So, three of those dots together, you'll join up.

We're avoiding though equilateral and right angle triangles.

We only want isosceles and scalene.

Okay? So, each dot will be one of the vertices.

You just need to join those three dots up to make isosceles and scalene triangles.

Best of luck guys.

I know you can do beautifully on this.

Keep it neat.

Off you go.

All right, guys, how was that? Pretty easy? Nice bit of exploring? Should we find out then how we did? I'm going to show you some of the ones that I came up with.

Okay? But this doesn't necessarily mean that they are right or wrong.

So, take a look here.

These are the few that I came up with and give it a few for each.

So, here, which type of triangles do you think I have here? Look at the properties.

Look at the sides and the angles.

What can you tell me about these three? I'm going to help you.

What is this telling you? These are all isosceles triangles.

And you could have come up with loads of different ones.

You could have had one that went from here to here, down to there.

Look at that, dreadful.

See why we need to use rulers.

I mean, that looks more like a tooth, but you get the picture.

All right.

So how about look at these and can you see how we have scaling triangles here as well? Okay? I'm sure you came up with lots of different ones yourselves.

So if you did, very well done.

Now, shall we just recap? I'm going to describe a triangle and what you need to do is you need to try and tell me which type it is.

Okay.

So thinking, thinking, thinking.

Don't forget.

Now, we have four types to remember, right angle, equilateral, scalene and finally I lost one, isosceles.

So, I'm going to describe one.

Can you tell me, which triangle I'm thinking of? Okay.

Think, think, think, think, think, think, think Mr.C Okay.

The triangle I'm thinking of has three sides.

Do you know which it is yet? Of course you don't because that's the property of all triangles.

Okay.

Now, my triangle has two identical sides.

So, two equal sides and two equal vertices.

What is my triangle? Yes.

Brilliant.

It's an isosceles triangle.

Well done.

Okay.

Here's my next one.

My triangle has no equal sides and no equal vertices.

Now, this could be one of two, couldn't it? But I've missed out a key piece of information that I would have told you if it was the other one.

So, yes it is scalene.

Here's the next clue.

This triangle, all three vertices measure 60°.

Yes.

Equilateral.

And so the last one, none of the sides are the same.

None of the angles are the same, but one of the angles is 90°.

One of my vertices is 90°.

What kind of triangle am I? Yes.

Right angle triangle because we know 90° is a right angle.

Fantastic.

Okay.

That is brilliant.

You are brilliant.

so until next session, very well done.

You've done a great job today.

So, I will see you soon.

That's it from me, Mr.C.

Bye, bye.