...without measure
It can be done using the central symmetry.
This video shows it in the DrGeo2 interactive geometry canvas: http://squeak.ofset.org/drgeo/5parts.ogg
The Undo/redo stack is used to replay the construction.
The figure is loaded from a DrGeo1.1 xml file.
Hilaire
etoys-dev@lists.squeakfoundation.org