So, you’ve got the hang of 2D shapes and their properties. Now it’s time to begin taking things to the next level with 3D shapes!
3D shapes are a little more complex than 2D shapes, but they really don’t have to be a big issue. You can learn all about the most common 3D shapes, including their names, properties, and features, with a little time. Luckily, we’ve compiled everything you need to know to master the basics of 3D shapes in today’s guide!
In this blog, we’ll cover:
What are 3D shapes?
First of all, we need to look at the basics of 3D shapes and what they actually are. Chances are, if you’re learning about 3D shapes, you’ve already got to grips with 2D shapes.
If not, no worries! Take a step back and make sure you know some of the most common 2D shape names and properties. Once you’ve checked this, you can look at 3D shapes.
- 2D stands for 2-dimensional. The easiest way to describe this is as a flat surface, such as a rectangular piece of paper. However, 3D is a little different and is something you’ll see more often in real life.
- 3D stands for 3-dimensional. It means that the shape has multiple sides and can be filled, like your favourite cereal box.
3D shapes are based on a similar 2D shape. For example, imagine a tennis ball. If you drew this on a piece of paper, you’d probably draw a circle.
However, tennis balls don’t really look like circles in real life because they aren’t flat! Instead, real-life tennis balls are called spheres – the 3D version of a circle.
Don’t worry – we’ll look at some of the common 3D shape names in the next section. The main thing to remember here is that 2D shapes are flat. By contrast, 3D shapes have a real-life shape with depth and fill. For example, compare a sheet of paper (2D) to a cardboard box (3D).
Common 3D shape names
Before we go further, we should look at some of the most common 3D shape names. It’s also helpful to look at their 2D equivalents. These include the following:
2D: square – 3D: cube
2D: rectangle – 3D: cuboid
2D: circle – 3D: sphere
2D: semicircle – 3D: hemisphere
2D: triangle – 3D: triangular pyramid
Some other shapes don’t have a direct 2D version. For example, a cylinder is made up of two circles at either end with a curved edge between them. A cone (like an ice cream cone!) has one circular face and a curved base, ending at a point.
Properties of 3D shapes
To understand 3D shapes, you need to understand their properties. We’ve outlined some of these as follows. Plus, we’ve given a few examples for some of the most common 3D shape names below.
First of all, we need to look at faces. A face for a 3D shape is the number of ‘panels’ it has, with each face bordered by edges.
For example, if we look at a cube, it’s made up of 6 faces. There are two square faces on the top and bottom and four square faces around the outside of the cube.
This is also true for cuboids. Cuboids have a rectangular face on the top and another on the bottom, and four around the sides.
Almost all 3D shapes will have at least three or more faces.
However, a curved surface doesn’t have any edges. Therefore, we say it only has one face. As such, a cone will only have two faces, and a sphere has just one face.
Edges are found on the outside of a face and are very similar to sides on a 2D shape. They show where one face meets another.
The easiest way to imagine this is to look at a cube. A cube has six faces, each of which is a square. Since a square has four sides, the top and bottom faces of the cube each have four edges. Then, there are also another four edges around the side of the cube; as such, the total number of edges for a cube is 12.
Meanwhile, for a cylinder, there are two edges – one edge where each circle base meets the body of the cylinder. Cones only have one edge since they only have a single circle face joining onto a curved face.
All 3D shapes have at least one edge. The exception is spheres that do not have any (since there is only one face and no other faces to join).
All 3D shapes have vertices, except for spheres and hemispheres. Vertices are “points” on the shape where two edges meet. For example, imagine you had a cereal box, and you touched the pointed corners; each of these is a vertex.
Some common examples include cubes and cuboids, which have eight vertices each, and triangular pyramids which have six vertices. However, a cylinder or a sphere wouldn’t have any vertices, as there are no points where two lines meet.
All 3D shapes have volume, which is similar to the area of a 2D shape. Volume measures the “fill” of a shape – in other words, how much space is inside the shape.
The easiest way to think about this is to consider your favourite can of fizzy drink. This can is a cylinder, meaning it is 3D; as such, it has volume.
The volume of this can says how much drink the can holds; in the case of a can of drink, usually, the volume will be around 330ml or 11oz. Most volume is measured in either cm3, ml (millilitres), or oz (ounces).
You’ll probably see shapes measured in millilitres, litres, or ounces in real life. However, in your maths class, your teacher will probably ask you to use cm3.
Ready to put your learning into practice?
How to work out the volume of a 3D shape
Volume is one of the most important 3D shape properties you’ll need to know. As such, you should always try to understand it carefully. This will help you to be sure you’re set for anything your maths teacher might throw at you!
Calculating the volume of a 3D shape is easy. However, you’ll need to remember the right formula for the shape (like with calculating areas of 2D shapes).
Some of the most common volume calculations include:
Cube: Length X Width X Height
Cuboid: Length X Width X Height
Triangular pyramid: 1/3 X Base Area X Height
Calculating the volume of a sphere is a little more tricky and involves a figure called π (3.1415926…). The calculation for spherical volume is (4/3) πr3 or 4/3 times π times the radius cubed.
For a hemisphere, the calculation is the same but halved. However, you probably won’t need this until you begin doing high-level maths calculations.
3D shapes don’t have to be scary! They’re actually quite simple to understand. So, we hope you now know more about the common 3D shape names and properties, such as faces, edges, and vertices.
For even more ways to explore 3D shapes, download the DoodleMaths app! It’s filled with fun interactive exercises and educational games specifically exploring shape and volume, making it the perfect way to bring your child’s learning to life. And best of all, you can try it for free!