Lesson video

Welcome to another video.

And in this lesson, we'll be looking at horizontal and vertical lines.

Now again, same as the last lesson, this will be another recap lesson on content that you should have already covered in Year 7.

And I'm Mr. Maseko.

Get your pen, your pencil, your ruler and your notebook.

And let's begin.

Okay, try this activity.

Pause the video here and give this a go.

Okay, now that you've tried this, let's see what you've come up with.

Well, a few statements that the students have come up with, well, I can name some coordinates on the green line, but what coordinates could be name on my green line? Well, let's see what would be the coordinate of this point here.

Well, that another coordinate Well, this point here is what? This is Good.

Another coordinate on that line.

Well let's pick point D will point D that is.

Okay, I can find the coordinates of A, B, C and D.

We've got point D already what's point C? What point C or point C is.

Point A will that is.

Point B.

Well, that is Good, that's.

Find some midpoints.

What are midpoints? Well, the midpoint is the middle between two coordinates.

So let's pick some coordinates on this line more or less nice and easy.

Let's pick point A and point B.

Now what's the midpoint of point A and point B? Well, the middle is here at this coordinate, which is.

Just by looking at the graph, we were able to find the midpoint.

Any statements that you've come up with, for this graph on the red line.

What do we have all the y coordinates on the red line are always equal to 3.

On the green line, all the x-ordinates are always equal to 7.

On the blue line all the x coordinates are always equal to 2 and at the orange line all the y coordinates, are always is equal to we got it -3.

Those are just a few of the points that you could have come up with.

So in the Connect section, we're going to build on that idea that we were just discussing from the try this.

So one 4 coordinate on each of these lines.

Well, I'm going to pick the ones in the middle here.

So those 4 on the red line, what do we have well that is , that is that is , and also.

straightaway, what jumps out we already said it.

All the y-ordinates are always 3 for all those coordinates on the y-ordinates are 3.

You can do the same for the orange line and find all the coordinates for that is , , , and.

What you notice this time? All the y-ordinates on the orange line are always -3.

For our horizontal lines, what can we say? On our horizontal lines.

The y-ordinates stay the same.

So on your horizontal lines, what do we say the y-ordinates.

So the y-ordinates stays the same.

So that is for our horizontal lines.

So what do you think can be said about our vertical lines.

If in the horizontal lines, the y-ordinate stays the same.

What would stay the same on the vertical lines? Got it the x-ordinate.

Now can we show this if we use the blue line, and we can pick 4 coordinates on that line.

Well watch this, this is , that's , that's , and that is.

You see all that x-ordinates on that vertical line all the x-ordinates stayed the same.

Okay, knowing that different ordinates stay the same and horizontal lines and vertical lines in horizontal lines, what stays the same? Good, in horizontal lines, the y-ordinate stays the same and vertical lines what stays the same? the x-ordinates.

So can we use that fact to name these lines? Well, on that red line, what can we pull that line for on that red line, the y-ordinate is always 3.

So the y-ordinate is always 3.

So we can say for that red line, the y-ordinate is equal to 3.

That's our horizontal line, just the y-ordinate on that line is equal to 3.

Coz' the y-ordinate stays the same And on the orange line, Good, the y-ordinate is always equal to -3.

What about the two vertical lines? We'll start with the blue one on the blue line, that x-ordinate is always equal to 2.

And on the green line, well, the x-ordinate is always equal to 7.

So using this idea that we can name, horizontal and vertical lines in this way, we're going to use this idea in the independent task.

So pause the video here and give this task a go.

Okay, now that you're back, let's see what you drew.

Well, on the coordinate grid, draw the following lines.

The line y is always equal to 3 Well, where is y-ordinate of 3, well that's there.

So when is the line where the y-ordinate is always 3, that will be a horizontal line because the y-ordinate stays the same.

So you use a ruler to do this, All the x coordinate is always -2.

with an x -2 there x-ordinate stays the same.

So that is a vertical line through there, y is -5 for that.

Down here, x is 5, well that is here.

Now, what about the line y equals x? What did you come up with for this line? Was it vertical or horizontal? Well let's see is y is only equal to x.

So the y-ordinate is always equal to the x-ordinate when x is 1, if the y is always equal to the x, which means the y will be 1.

When x is 2, the y will be 2, x is 3, the y will be 3, and so on, and so forth.

Now, if you look at this, neither the x-ordinates or the y-ordinates stays the same.

So that is neither a horizontal or a vertical line.

And now would would do more with lines that look like this in a later lesson.

Now, can you plot some horizontal and vertical lines that go through each of these points, and states where they all intersect? That is where they cross if they do.

So pause the video here and give this a go.

Okay, let's see what you come up with.

Well, a horizontal line going through point A, or that could be the line.

So this line here, so what's that line on that line, the y coordinate is always 3.

So that is y = 3.

You could also draw a vertical line of x = -3.

And you see those two lines y = 3 and x = -3 intersect where? At , and that's the coordinate of point E.

x is -3, and y is 3.

You can do the same thing for a vertical line going through point G and a horizontal line going through point G and then same thing for point F.

And you can do this for all the points.

And then you can state any of these coordinates where those lines intersect, for example, this coordinate here.

So the line that goes through point G, the vertical lines, that is x = 1, well, that intersects with y = 3.

So what's the coordinate going to be? x = 1 and y = 3, that is ,.

So two when a horizontal line and a vertical line intersect.

The coordinate of the intersection points will always be well, what's, the vertical line called? x = 1, so the coordinate the x coordinate will be 1.

And what's the horizontal line called? That's y = 3, so the y coordinate with 3.

so if you would like to share your work ask your parent or carer to share work on Twitter, tagging @OakNational and #LearnwithOak.

Thank you for taking part in this lesson.

I will see you again next time.

Bye for now.