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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?
Counting Triangles
Triangles are formed by joining the vertices of a skeletal cube. How many different types of triangle are there? How many triangles altogether?
Age 11 to 14
Challenge Level
If you need some squared paper you can download it here.
Hint for finding the inverse of $R S$:
If I put on my t-shirt and then put on my jumper, how can I undo this?
Which item of clothing do I have to take off first?
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NRICH is part of the family of activities in the Millennium Mathematics Project.
NRICH is part of the family of activities in the Millennium Mathematics Project.