"The Pyramid of Cheops or the Great Pyramid is not only the largest of all megalithic monuments, but also probably the monument having been subject to most accurate surveys and most speculation.
One is most impressed during these surveys by the unprecedented exactness of bearings in the horizontal plane and in the four cardinal points. The largest height difference around the base-slab with the 230 m side is only 21 mm between the middle of the Northside and the Southeastern corner. The deviation from the North-South line is only 3'6", i.e. 3/60 of a degree.
The four square corners are laid out with such precision that it is hardly surpassed by modern building technique. Most exact is the Southwest corner where the angle is 16", i.e. 16/3600 of a degree too large, and the most deviating is the Northeast corner with 58" or about 1/60 of one degree."
Article extrait de "Discussions in Egyptology" 28 (1994), pp. 21-27, Oxbow Books, repris par Digital Giza : ICI