Topics
10. Shapes and angles
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Australia
Year 5

10.03 Nets of solids

Lesson
Practice

Are you ready?

Let's review features of  3D objects  to help us in this lesson.

Examples

Example 1

Here is a rectangular prism.

An image of a rectangular prism.
a

How many faces does it have?

Worked Solution
Create a strategy

Faces are the flat sides of a solid.

Apply the idea

It has 6 faces.

b

How many vertices does it have?

Worked Solution
Create a strategy

Vertices are the corners where edges meet.

Apply the idea

It has 8 vertices.

c

How many edges does it have?

Worked Solution
Create a strategy

An edge is the line where two faces meet.

Apply the idea

It has 12 edges.

Idea summary

A prism can be made with any polygon at its base.

Nets of solids

Let's look at how to make 2D representations of 3D solid objects.

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Examples

Example 2

Choose the net that folds to give the shape below:

An image of a rectangular prism.
A
The image shows a net of a solid. Ask your teacher for more information.
B
The image shows a net of a solid. Ask your teacher for more information.
C
The image shows a net of a solid. Ask your teacher for more information.
D
The image shows a net of a solid. Ask your teacher for more information.
Worked Solution
Create a strategy

Choose the net with the same number of faces as the solid and can be folded along its edges to make the solid.

Apply the idea

The solid has 6 rectangular sides, where the opposite sides are the same.

Looking at the options, we can see that options C and D have 6 rectangles.

If we folded option D then the opposite rectangles would be the same. This is not true for option C.

So the correct answer is Option D.

Idea summary

When we make a net of a solid, there may be more than one possibility. We can use the edges and vertices to help us, as well as the two dimensional (2D) shapes.

Outcomes

AC9M5SP01

connect objects to their nets and build objects from their nets using spatial and geometric reasoning

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