[98] Petrie concluded: "but these relations of areas and of circular ratio are so systematic that we should grant that they were in the builder's design".[99] Others have argued that the ancient Egyptians had no concept of pi and would not have thought to encode it in their monuments and that the observed pyramid slope may be based on the seked choice alone.[100]

Alignment to the cardinal directions
The sides of the Great Pyramid's base are closely aligned to the four geographic (not magnetic) cardinal directions, deviating on average 3 minutes and 38 seconds of arc, or about a tenth of a degree.[101] Several methods have been proposed for how the ancient Egyptians achieved this level of accuracy:

The Solar Gnomon Method: The shadow of a vertical rod is tracked throughout a day. The shadow line is intersected by a circle drawn around the base of the rod. Connecting the intersecting points produces an east–west line. An experiment using this method resulted in lines being, on average, 2 minutes, 9 seconds off due east–west. 