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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.