The Epitrochoid 

Introduction:The epitrochoid has as special cases the circle (a = 0), the limaçon (a = b), and the epicycloid (h = b). In general, it has a/b loops. Definition:Geometrically, the epitrochoid is traced by a point P attached at a distance h to the center of a circle of radius b rolling along another circle of radius a. Properties:
