### Video Transcript

Fill in the blanks in the following
sentences about triangles. All triangles what. Have more than three sides, are
yellow, or have three sides. But only some triangles what. Have three corners, are green, or
have three straight sides.

This question is all about the 2D
shape, the triangle. And we’re given some pictures to
help us. We’re given two very short
sentences to complete. Did you notice the main difference
between them? There are two very small words, but
they make a lot of difference. In the first sentence, it’s the
word “all.” This means everything, doesn’t it,
every single one. So to complete this sentence, we’re
looking for a feature of triangles that every single triangle has. This is going to be one of the
things that makes a triangle a triangle.

Now, the small word in our second
sentence is the word “some.” This word is different because it
means not all, part of the whole amount. And when we complete this sentence,
we’re looking for a feature that not every triangle has in common, only some of them
do. Let’s start with our first sentence
then. All triangles what. Can we say that all the triangles
in the picture and all the triangles we could ever draw have more than three
sides? If we count the number of sides
that our first triangle has, there are one, two, three.

We can use the picture to help us
here. And we can say that all of the
triangles in the picture do have three sides. And even if we were to draw some of
our own, they would also have three sides. We can’t say all triangles have
more than three sides, can we? We can’t even say some triangles
have more than three sides. We’d have to say, no triangle ever
has more than three sides.

Now, what about the color of these
shapes? Can we say all triangles are
yellow? Although one of our triangles in
the picture is a yellowy-orange color, we know that triangles can be any color. They could be pink, green, or
white, like in the picture. But they could also be blue stripy
or shiny silver. I suppose we could say some
triangles are yellow. The color of a triangle isn’t
something that makes it a triangle. Now, we’re only left with one
possible answer. All triangles have three sides. Well, we don’t need to think too
much about this, do we? We’ve already talked about the fact
that every single triangle has got three straight sides. We can say all triangles have three
sides.

Now let’s think about our second
sentence. But only some triangles what. Do only some triangles have three
corners. Well, we can see on our first
triangle in the picture that it does have three corners. In fact, so do all the others. This isn’t something that only some
triangles have. This is something that’s true of
every triangle. It’s one of those features that
makes a triangle a triangle. We could actually use this phrase
in our first sentence, “All triangles have three corners.” Let’s try our second phrase. Can we say only some triangles are
green? Yes, we can, can’t we?

As we’ve said already, triangles
can be any color. Of course, only some triangles are
green, knowing the color of a shape doesn’t help us identify what sort of a shape it
is at all. And let’s just check our last
phrase. Only some triangles have three
straight sides. Not at all. As we’ve found out already, all
triangles have three straight sides. In this question, we’ve thought
about the things that are always true of triangles and the things that are sometimes
true. And this helped us complete the
sentences. All triangles have three sides. But only some triangles are
green.