Lesson video

Hi everyone, I'm Miss Mitchell.

Today at Maths we're going to be identifying right angles in shapes.

In today's lesson we are going to be learning what a right angle is, you will then complete a talk task an independent task and then a quiz.

For today's lesson you will need a pencil and some paper.

You will also need some items in your home to measure.

Please ask a parent or a carer before touching any items. I need your help.

So a mysterious shape has stolen this boy's pencil case and we need to know whodunnit.

Now we know the thief has more than three sides, we know that he has less than five sides, and we also know that there were no right angles at his vertices.

Now we have a star word to day and the word is right angle.

So can you say "Right Angle"? Right angle.

Right angle.

Right angle.

A right angle is a turn of 90 degrees.

So this part here, this here is a right angle.

So this inside part here is 90 degrees.

And any corner that has 90 degrees is called a right angle.

Now quarter to and quarter past on a clock are also examples of right angles.

Because that means this part in here, and this part in here are both 90 degrees.

Right angles can also be found where two lines meet which makes an L shape as you can see here.

And now this L shape also you can make a square.

So a right angle can usually be found in the corner of the rectangle or a square and it makes a square which is why the symbol of a right angle is a square.

For now, it's a time for your Talk Task.

What I would like you to do, I would like you to find five examples of right angles in your home.

So you're going to walk around your home and you're going to say it out loud.

For example, my coffee table on the corner of my coffee table I can see a right angle.

It is 90 degrees.

So I will say this is a right angle because it is 90 degrees.

I might keep walking around my home and I can see my microwave.

And I can see my microwave has four right angles.

Can you please now pause the video and have a go.

Here is a shape.

What shape is this? This is a square.

and I know it's a square because all four lengths are the same size.

Now in this square can you see any right angles? Put your thumbs up or a thumbs down.

That's right.

This square has one, two, three, four right angles.

All of this four corners are 90 degrees.

Here is a triangle.

Can you put your thumbs up or your thumbs down can you see a right angle in this shape? That's right.

There is one right angle in this triangle and that is over here.

So that means this triangle is called a right-angled triangle.

Because not all triangles have right angles.

So I can see here that this is 90 degrees.

Are these two corners 90 degrees? No.

No, they are not.

Only this corner is 90 degrees which makes it a right-angled triangle.

Fantastic.

What shape is this? It has five sides.

That's right.

It is called a pentagon.

Can you say "pentagon"? Now can you put your thumbs up or your thumbs down can you please tell me whether this shape has a right angle.

Well done if your thumbs are down.

There are no right angles in this pentagon.

For your Independent Task, I would like you to look at the shapes and identify whether they have right angles.

Please pause the video now and press play when you are ready for the answers.

And here are the answers.

So you can see that these four angles on this shape and these four angles on this shape are right angles.

Great work today.

If you would like to share your work with Oak National then please ask your parent or carer to share your work on Twitter tagging @OakNational and #LearnwithOak Fantastic work Now let's see what you can remember by completing the quiz.

See you later.

Bye.