#### You may also like

How can the same pieces of the tangram make this bowl before and after it was chipped? Use the interactivity to try and work out what is going on!

### Teddy Town

There are nine teddies in Teddy Town - three red, three blue and three yellow. There are also nine houses, three of each colour. Can you put them on the map of Teddy Town according to the rules?

### Four Triangles Puzzle

Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?

# Dotty Circle

##### Stage: 2 Challenge Level:

Watch the film below.
Full Screen Version
This text is usually replaced by the Flash movie.

Try to describe what happens in the film to someone else.

Imagine the dot starts at the point (1,0), turns through $20^\circ$ and then stops:

If the point now carries on, through how many degrees must it turn to finish the same height above or below the horizontal axis as it was when it had gone through $20^\circ$?

Can you find a general rule for explaining when the dot will be this same distance from the horizontal axis?

You might like to try Round and Round and Round after this problem.

This film is based on one developed by Alf Coles - thank you to Alf for allowing us to use these ideas. You can watch all Alf's films at http://www.mathsfilms.co.uk