A tetrahedron (plural tetrahedra) is a solid with four triangular faces. How many different tetrahedra can you make using the four different types of triangle shown in the diagram if you have an unlimited number of each type?
Type R are right angled isosceles triangles with sides a, a and b units.
This practical activity involves making a skeletal model of an icosahedron by tying together sticks made from paper rolled tightly around pieces of string. Make 6 rhombuses as shown with 5 sticks for each one.
Describe 3D objects that could have made these shadows. There is more than one answer for each shadow.
Can you draw different shadows that could be made by the same objects?
Click here for […]
The Great Pyramid at Giza in Egypt was built around 2500 BC. The pyramid has a square base ABCD with sides 232.6 metres long. The distance from each corner of the base to the apex E was originally 221.2 metres.
In March 2014 and February 2015 Bubblz the Mathematical Clown and the Pyraloons built Guinness World Record breaking Balloon Model Sierpinski Pyramids to raise funds for AIMSSEC. The photo shows the triumphant team in a shopping mall in Cambridge, UK and their 6.5 metre high pyramid.
The smallest pyramid is made from […]
To make a model showing how cubes are made up of three square based pyramids, you will need a cardboard box, some string, some colouring pens and a knife or scissors to cut the box.
From one corner of a box cut squares all exactly the same size to form 3 faces of a […]
Copy this diagram. To draw a cube first draw a square, then draw another square the same size that looks as if it is behind the first square, then join the vertices with four parallel lines.
Why do the diagonals of a unit cube have lengths √2 and √3?
What are the lengths of the […]
The edges of the triangle are the same length. What about the […]
A tetrahedron and an octahedron, both have equilateral triangular faces.
One face (not shown) is plain yellow.
The other five faces have squares on them coloured blue, orange, pink, green and red.
Which face is opposite the blue one?
Draw a net of this cube and label the six faces.