# Tracing a Cyclogon: Roulette of a Polygon Rolling along a Line

Tracing a Cyclogon: Roulette of a Polygon Rolling along a Line

This Demonstration traces the path of a point attached to a regular polygon rolling without slipping along a straight line. The point is called the pole or tracing point.

If the pole is a vertex of the polygon (Snapshot 1), the traced curve is called a cyclogon.

If the pole is inside the polygon, the curve is a curtate cyclogon (Snapshot 3). If outside the polygon, it is a prolate cyclogon (Snapshot 4).