0000857005-06-000006 8-K 1 20060228 8.01 20060228 20060228 PARAMETRIC TECHNOLOGY CORP 0000857005 7372 042866152 MA 0930 8-K 34 000-18059 06648592 140 KENDRICK STREET NEEDHAM MA 02494 7813705000 140 KENDRICK STREET NEEDHAM MA 02494 8-K 1 ptc8k2282006.txt PTC 8-K FEBRUARY 28, 2006