Five Platonic Solids

There are five platonic solids, tetrahedron, hexahedron, octahedron, dodecahedron and icosahedron. They are regular solids which satisfy the following conditions:

All sides are equal in length, all the angles on all the faces are the same,  and all the faces are identical in size and shape. At each corner of a platonic solid, the same number of faces, or surfaces meet.

These conditions are met by just five regular solid shapes. But while it's easy to answer the question, "how many platonic solids are there" it must be noted that there are irregular shaped tetrahredons, octahedrons etc too! But these do not qualify as platonic solids because as their shapes are not 'regular' then their angles and sides cannot be the same either. When people talk about tetrahedrons, dodecahedrons etc they are normally referring to the regular shapes, ie platonic solids!

In 'Shapes and Nets, the five platonic solids can be investigated by moving, rotating and scaling them. The software will display the platonic solid nets for all five shapes and these can be printed to build them into paper models. Each of the faces can be applied with different colours or images.

Children can engage with activities in 'Shapes and Nets' to investigate the nets of platonic solids. A favourite one is the dice activity where children can place an image onto each face of the solids, rotate and scale them then display and print their nets, it's a great way to learn about the shapes. Below are examples showing the platonic solids nets for all five shapes:

equilateral triangle shapes which have equal length sides.

which has eight faces and is made

from equilateral triangles.

So when discussing platonic solids it is normal to drop the term 'regular' and talk about dodecahedrons, rather than regular dodecahedrons.