Polygon:
An interactive curve or polygon.
A particle is a 2D drawing element that draws a poligonal curve specified by the coordinates of their vertices points. If the Closed property holds the value true, then the points are taken as the vertices of a closed polygon.
The vertices of the polygon (or of the curve) respond to user interaction either moving the whole polygon (default behavior) or resizing it (see property Resizable), invoking up to five different actions.