Video Transcript
Anthony has sorted these shapes
into two groups, group one and group two. Why does this shape belong in group
one? Because it is green, because it has
more than four sides, or because it is a rectangle.
We can tell by reading this
question that Anthony has done some shape sorting here. He’s had some 2D shapes, and he
sorted them into two groups. Now, this question is really
interesting because it gets us thinking about what different 2D shapes have in
common. In particular, we’re thinking about
the 2D shapes that are in group one because we’re given a picture of a shape and
we’re asked, why does it belong in group one? Can you see it in group one? Looks like this shape here, doesn’t
it? And why has Anthony decided to put
this particular shape with all the others in group one?
Is it because it’s green? Well, you can understand why
somebody might think this was the right answer. It is a green shape, and all the
other shapes in group one are also green. So do you think the rule for
putting a shape in group one is that they’re green? No, because if we look in group
two, we can see a green circle and a green triangle. Just because some shapes are the
same color doesn’t mean they’re the same type of shape at all. Anthony hasn’t sorted these shapes
by color, has he?
Now, do you think this shape
belongs in group one because it has more than four sides? Well, if we actually count the
number of sides that this shape has, we can see that it has four sides, not more
than four sides. So this statement isn’t true at
all. Now, this is where the question
gets interesting because if this statement said, because it has four sides, it still
wouldn’t be the right answer. Can you see that one of the shapes
in group two also has four sides?
Anthony hasn’t chosen to sort these
shapes based on the number of sides that they have. This only leaves us with one
possible answer. This shape belongs in group one
because it’s a rectangle. And Anthony has sorted out all the
rectangles and put them all together in group one. And if we look at all the shapes in
group one, there are some features that they all have in common. These are the things that make them
rectangles. Each one of them has four square
corners. And they all have four straight
sides. These are the things Anthony was
looking for when he wanted to sort these shapes into group one, not the fact they
were green. This shape belongs in group one
because it is a rectangle.
