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Rotating Triangle

What happens to the perimeter of triangle ABC as the two smaller circles change size and roll around inside the bigger circle?

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Draw a 'doodle' - a closed intersecting curve drawn without taking pencil from paper. What can you prove about the intersections?

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Russian Cubes

I want some cubes painted with three blue faces and three red faces. How many different cubes can be painted like that?

Circle Box

Stage: 4 Challenge Level: Challenge Level:2 Challenge Level:2

Four circles of diameter 1 unit fit easily enough in a square of side 2 , but what is the smallest square into which we can fit 3 circles of diameter 1 unit?

Three Circles in a Square