Ti sugerisco questo link per la dimostrazione del teorema di Eulero: http://www.mclink.it/personal/MC2113/geometria/LineaEulero.html Ivano -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.16.10/625 - Release Date: 13/01/2007 17:40