Question Video: Identifying Vertical and Horizontal Lines Mathematics

Video Transcript

True or false: A horizontal and a vertical line will form a right angle.

This question is made up of a statement. We’re told that a horizontal and a vertical line will form a right angle. But that statement might not be correct. We need to decide. Is it true? Or is it false?

Now, for us to work out the correct answer, there are a few words we need to remind ourselves of here. There’s the word horizontal, vertical, and also the words right angle. Do you remember what each one of these words means? If something is horizontal, it runs from left to right without sloping. It’s completely level. Can you see which one of the two lines in the picture runs from left to right without sloping? It’s this one here, going across the screen.

Now, there’s one more line in our picture. This doesn’t run from left to right though. That’s because this is a vertical line. This line runs up and down without sloping. This is completely straight from top to bottom without going left or right in any way. So, we can see where our horizontal and vertical lines are.

And our statement tells us that these sorts of lines will form a right angle. Do you remember what a right angle is? A right angle is where two lines meet together to make an angle of 90 degrees, or a square corner. This is why the symbol for a right angle is often a little square drawn in the corner. So, what do you think? If we have a horizontal and a vertical line, will they make a right angle?

Well, if we look at the two lines in our picture, they’re not even touching. They haven’t formed a right angle. But our question doesn’t say, “This horizontal and this vertical line have made a right angle.” It just tells us that if we take a horizontal line and we take a vertical line, they’ll make a right angle. So, to find our answer, all we have to do with our horizontal line is carry on drawing it. There we go. We only needed to add a little bit more. And now our horizontal and vertical lines are touching.

Do they meet at a square corner? Yes, we can see that they’ve made one, two right angles. And if we continue our horizontal line a little bit more, there are more right angles. And this fact is true of any horizontal and vertical lines. Horizontal plus vertical equals a right angle. Horizontal plus vertical equals a right angle. So, although we can make right angles in lots of other ways — can you see this example at the top? Neither of these lines are horizontal or vertical, are they? They’re both sloped, but they still make a right angle. We know that the statement is correct.

A horizontal and a vertical line will form a right angle. This sentence is true.