### Chess

What would be the smallest number of moves needed to move a Knight from a chess set from one corner to the opposite corner of a 99 by 99 square board?

### 2001 Spatial Oddity

With one cut a piece of card 16 cm by 9 cm can be made into two pieces which can be rearranged to form a square 12 cm by 12 cm. Explain how this can be done.

### Screwed-up

A cylindrical helix is just a spiral on a cylinder, like an ordinary spring or the thread on a bolt. If I turn a left-handed helix over (top to bottom) does it become a right handed helix?

# Making Rectangles, Making Squares

##### Age 11 to 14 Challenge Level:

The $30$ $^\circ$ , $30$ $^\circ$ , $120$ $^\circ$ isosceles triangles are made by bisecting the equilateral triangles and putting the two pieces together the other way - like this: