About

The Cohan Circle consists of two overlapping circular discs. The distance between the centres is exactly one radius length. The discs are made up of many pieces with curved sides, which allow them to be rotated any number of 1/6th turns. Each disc has 6 blank triangles, and 12 petal-shaped pieces. As some pieces are shared between the two discs, there are all together 10 triangles and 19 petals. The 19 petals come in 4 colours - 6 red, 6 green, 6 blue, and 1 white. The aim is to make the 6 peripheral pieces of each disc of a single colour, forming two circles, and also place the white piece in the centre. This puzzle was invented and patented by Hooshang Cohan, number US 4,580,783 published 8 April 1986. It may have been sold as the 'Magic Circle Puzzle', as the solution booklet has that title covered by a label with the correct name. Arusloky is a recent version of this puzzle, made in Spain. It has a slightly different colour scheme, with 6 red petals, 6 yellow petals, and everything else blue. Its starting configuration has a red and a yellow circle. If your browser supports it, you can click on the link below to play with a Javascript version of both the Cohan Circle and Arusloky.