KHUFU IS PYRAMID was an architectural and engineering feat. To produce a structure of its immense size phenomenal knowledge and organization were required. The Great was constructed with approximately 2300000 limestone and granite blocks weighing from 2.5 to 50 tone each. How were these huge stones cut Egyptologists believe that copper and bronze saws must have been used to shape the blocks but there it is not know for certain how the blocks were put in to place several theories have been proposed. One theory suggests that the Egyptians constructed a straight or spiral ramp that was raised as the work proceeded . This ramp covered whit mud and water facilitated the movement of the blocks which were pushed into place. Experts estimate that as many as 100000 slaves were needed to build the pyramid which was erected during Khufu is reign over a period of approximately 20 years. To this day many questions remain unanswered. And there are other mysteries.