Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsTracing a Line Segment Moving along an Ellipsehttp://demonstrations.wolfram.com/TracingALineSegmentMovingAlongAnEllipse/]]>http://demonstrations.wolfram.com/TracingALineSegmentMovingAlongAnEllipse/