Not sure you remember this from junior hight? ;-) https://plus.google.com/+DrgeoEu/posts/E5GvDBvZcmw
The next step: to show how Pharo let you (user) easily integrate this script as a system extension. So students can play with cobweb diagram with a two lines script. Hilaire -- Dr. Geo http://drgeo.eu http://google.com/+DrgeoEu
