The Great Pyramid, built by Khufu (Cheops) in 2550 BC, for example, stands an impressive 46m (150ft) high, with a slope of 51degrees. The original pyramids serve as a testament to the mathematical skill of the Egyptians, a skill that stimulated Greek mathematicians, including Pythagoras, to perfect their work. They hold the key to understanding the structure of Egyptian society. The pyramid form, in particular, still pays an important role in modern architecture, and can be seen rising above cemeteries and innumerable shopping centres, and at the new entrance to the Louvre Museum, Paris. Egypt's magnificent stone buildings - her pyramids and temples - have inspired innumerable artists, writers, poets and architects from the Roman period to the present day.