Sine, cosine, tangent

problem

The Dodecahedron

Age

16 to 18

Challenge level

What are the shortest distances between the centres of opposite faces of a regular solid dodecahedron on the surface and through the middle of the dodecahedron?
problem

Over the Pole

Age

16 to 18

Challenge level

Two places are diametrically opposite each other on the same line of latitude. Compare the distances between them travelling along the line of latitude and travelling over the nearest pole.
article
The History of Trigonometry- Part 1

The first of three articles on the History of Trigonometry. This takes us from the Egyptians to early work on trigonometry in China.
page
Making Maths: Clinometer

You can use a clinometer to measure the height of tall things that you can't possibly reach to the top of, Make a clinometer and use it to help you estimate the heights of tall objects.
interactivity
Round and Round a Circle

Age

14 to 16

Challenge level

Can you explain what is happening and account for the values being displayed?
article
Muggles, Logo and Gradients

Logo helps us to understand gradients of lines and why Muggles Magic is not magic but mathematics. See the problem Muggles magic.
article
History of Trigonometry - Part 2

The second of three articles on the History of Trigonometry.
article
History of Trigonometry - Part 3

The third of three articles on the History of Trigonometry.
article
Why Stop at Three by One

Beautiful mathematics. Two 18 year old students gave eight different proofs of one result then generalised it from the 3 by 1 case to the n by 1 case and proved the general result.