Polylines
The Poly-line tool creates a polygonal shape made of a connected series of straight and curved segments. Curved segments are arcs drawn by center or by tangent.
The polyline object offers some advantages over individual elements, such as the ability to modify a point without having to rebuild the sequence, or grab a segment by its mid-point to stretch the shape. Also, since a polyline is one object, its perimeter and area are always available and up-to date.
