P is a point on the circumference of a circle radius r which rolls,
without slipping, inside a circle of radius 2r. What is the locus
The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design...
What happens to the perimeter of triangle ABC as the two smaller
circles change size and roll around inside the bigger circle?
Edison from Shatin School included some edited
versions of the diagram given in the hints to support his
Well done Edison, can anyone think of any
other interesting projections to aim for?