Seven Coins Puzzle

Draw an {N/D} star polygon - a polygon whose N vertices are uniformly distributed on a circle, but are connected by counting the D-th neighbor. Regular polygons correspond to D = 1, and their symbol is usually abbreviated to {N}.

In the applet the symbol {N/D} appears in the lower right corner. Both numbers can be modified by clicking a little off their center lines. When N and D have a common factor, there are conflicting view points as to whether the configuration of nodes and edges represents a single polygon or a collection of polygons with fewer vertices. However, for the puzzle we shall assume that N and D are mutually prime. In the classical case, N = 8 and D = 3. The object is to place 7 coins (N - 1 in general) at the vertices of the star. A coin may only be placed by dragging the cursor along an edge from one vertex to another.

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at, download and install Java VM and enjoy the applet.

What if applet does not run?


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