### 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.