Lesson Video: 3D Shapes | Nagwa Lesson Video: 3D Shapes | Nagwa

# Lesson Video: 3D Shapes Mathematics • Kindergarten

In this video, we will learn how to identify 3D shapes regardless of their size, orientation, or color.

09:31

### Video Transcript

3D Shapes

In this video, we’re going to learn how to identify some common 3D shapes. And we’re going to learn how to do this regardless of their size, what color they are, and no matter what position we put them in. In particular, we’re going to concentrate on six different shapes. Let’s go through them one by one to find out more.

This is a sphere. The first thing we can say about a sphere is that it has a curved surface all around. And it’s this curved surface that means a sphere can roll. Spheres are ball-shaped. This marble is a sphere, and so is this beach ball. They may be different sizes, but they’re both spheres. We know this because they have a curved surface all around, and we can say that they’re ball-shaped.

How can we recognize a cylinder? This is a cylinder. The first thing we can say is that it has a curved surface. But if we look carefully, we can see that this shape has got two flat surfaces too. They’re opposite each other, one at each end of the cylinder. This tin of beans is a cylinder.

We can see that it has a curved surface all the way around, and the flat surface at each end means it’s perfect for stacking in the supermarket. These objects may be different colors, but we can see that they’re both the same 3D shape. They have curved surfaces and two flat surfaces, one at each end. They’re cylinders.

This shape is a cone. Like a cylinder, it has a curved surface too. It also has a flat surface, but only at one end. And we can’t see this in the picture of the cone that we’ve got. Let’s turn it around. There we go. Now, we can see the flat surface a lot more clearly, but what’s at the other end of the cone? We can see a point. Cones have a flat surface at one end and a point at the other.

This is a cone. We can see the curved surface, a point on one end. And although there isn’t a flat surface at the other end, we can see that there should be one. This sort of cone has been hollowed out so that we can fill it with something delicious. It’s an ice cream cone!

So far, we’ve thought about three shapes that have curved surfaces. Now, let’s identify some shapes that only have flat surfaces. This is a pyramid. All of its surfaces are flat. It has a flat surface underneath or on top, depends which way we look at our pyramid. Let’s just say it has a flat surface at one end, but what’s at the other end? Just like a cone, there’s a point at the other end.

The ancient Egyptians built huge pyramids. So, we can identify pyramids by noticing that all the surfaces are flat, and they have a flat surface at one end and a point at the other.

Now, it’s helpful to compare our last two shapes, so let’s look at them at the same time. First of all, the cube. This is a cube. Again, we can see that it has no curved surfaces; they’re all flat. A dice is a cube, and thinking about a dice is really helpful. We know that there must be six surfaces to a cube because our dice goes up to six. Each surface has a different number on it, but also each surface on a cube is the same shape.

We could turn our cube into different positions. We could even decorate the surfaces in different ways. But no matter how we look at our cube, each of the six flat surfaces is exactly the same shape. That’s really important. And it’s really important because our next shape, the rectangular prism, also has six flat surfaces.

But if we look carefully at our rectangular prism, it looks a little bit like a cube that’s been stretched. And if we turn a rectangular prism, it helps us to see that not all the surfaces are the same shape. Can you see how this surface here on the end is a lot smaller and thinner than this surface with a white arrow on it? A rectangular prism has six flat surfaces, but they’re of different sizes.

A brick is a rectangular prism, as are many other boxes that we buy when we do our groceries. Another word we may come across is cuboid. Like we said, a rectangular prism is a little bit like a stretched or a squashed cube.

Now that we’ve learned about spheres, cylinders, cones, pyramids, cubes, and rectangular prisms, let’s have a go at answering some questions where we have to identify these 3D shapes.

Choose another cube.

In this question, we’re shown a picture of a 3D shape. It’s a cube. And we’re asked to choose another cube. We need to choose from the three possible 3D shapes at the bottom, but none of the shapes looks exactly like the cube in the picture. They’re all different colors. They look like they’re different sizes. Or maybe, the cube we’re looking for is in a different position.

Let’s remind ourselves what we know about cubes to help spot which of the shapes is a cube. One thing we know about cubes is that all the surfaces on a cube are flat. There’s nothing curved about a cube at all. But if we look at our first shape, we can see that it does have a curved surface, goes all the way around. This shape can’t be a cube. It’s a cone.

The second shape also has a curved surface. And again, we can see it goes all the way around. This shape isn’t a cube either. We call this shape a cylinder. And so, we know the green shape is a cube. All of its surfaces are flat. And although it’s a different size, a different color, and in a different position to the cube in the picture, we know that this makes no difference at all. It’s still a cube. The green shape is a cube.

Is this a sphere?

We can see a picture of a red 3D shape here. And we need to find out whether this shape is a sphere or not. To help us, let’s remind ourselves what makes a sphere. Firstly, we know that spheres have a curved surface all around. This shape has a curved surface all around. Maybe it’s a sphere then.

Something else we know about spheres, though, is that they’re ball-shaped. Does the red shape look like a ball? Well, no. It looks like a ball that’s been squashed. Although our red shape does have a curved surface all around, it’s not ball-shaped. And so, we can say no, it’s not a sphere.

How many cylinders are there?

In this problem, we’re shown eight different 3D shapes, and we need to count the number of cylinders that there are. But for us to be able to do this, we need to remind ourselves what makes a cylinder. Firstly, we know that cylinders have both curved and flat surfaces. These two shapes on the top row don’t have any curved surfaces at all. Let’s cross them out. They’re not cylinders. And although this shape on the bottom row does have a curved surface, it doesn’t have any flat surfaces. It’s a sphere.

So, we’re left with five possible shapes. What do we know about the flat surfaces on a cylinder? We know that cylinders have two flat surfaces, one at each end. If we look carefully, we can see that some of our shapes only have one flat surface. And at the opposite end, they have a point. We know these shapes are cones.

And if we look at the two shapes we have left, we can see that they do have two flat surfaces. One, two. There are only two shapes here that have a curved surface and flat surfaces, one at each end. So, we can say there are two cylinders.

Now, what have we learned in this video? We’ve learned that it doesn’t matter what size, color, or even what position a 3D shape is in. We’ve learned how to identify different 3D shapes using what we know about their features.