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'Shaping Up' printed from http://nrich.maths.org/
For this activity, you'll need to print out these cards
are 27 different cards in total. Here is a picture of just three of
What rules were used to make the 27 cards, do you think?
Have all the possible combinations of two shapes been
How do you know?
If the rules were changed so that a card has two triangles, what
would the complete set of cards contain?
This problem is based on ideas
from "It Makes You Think", a book and CD of mathematical puzzles
and problems, produced by Jill Mansergh and available from
The Association of Teachers of