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Unit C2 Section 2
Constructing Nets

A net for a solid can be visualised by imagining that the shape is cut along its edges until it can be laid flat.

Worked Examples

1

Draw the net for the cuboid shown in the diagram.

Imagine making cuts as below:

  • cut along the edges AB, BC and CD to open the top like a flap.
  • then cut down AE, BF, CG and DH, and press flat to give the net below.
2

Draw the net for this square-based pyramid.

First imagine cutting down the edges AD and AC and opening out a triangle.

Then cutting down AB and AE gives the net below.

Exercises

Draw and cut out four equally sized equilateral triangles.

(a)

How many different ways can they be arranged with sides joined together?

One example is shown.

(b)

How many of your arrangements of triangles form a net for a tetrahedron?

Which one of these nets can be folded without any of the sides overlapping to make a cube?

The diagram above shows a pyramid with four equal triangular faces.

Each edge is 4 cm long.

Below is one of the faces.

(a)

What is the special name given to this kind of triangle?

triangle
(b)

What is the size of each angle of this triangle?

°