The Seked Pyramid
Most true pyramids in the 4th and 5th dynasties had the angles at their slopes defined using a seked or ratio (Rossi 2003, p. 242). After the development of the true pyramids at Dashur a further systematic standardization in pyramid design took place. The cubit stick was now used to systematically plan the construction of pyramids, and thereafter all but one of the major true pyramid projects from the 4th and 5th dynasties were divided into 7 parts and built with a 6-stepped structure at their core, i.e. the type labelled seked pyramids in this book. Each palm on the cubit stick now represented one mastaba at a scale proportional to the pyramid’s height in Royal cubits (Fig. 76). It should be noted that this was a different way of using scales than what we are familiar with today. Instead of deciding on a given scale before starting the drawing, all seked pyramid projects would have started with a drawing in which the pyramid was 1 Rc high. Thus, the first drawing had its scale determined by the pyramid’s height measured in Royal cubits.
By the 4th and 5th dynasties, the use of the seked to determine the slope of the pyramid would have become natural, given that the drawing of the pyramids was 1 Rc high. This may be the reason why most pyramids dating from this period have a height in Royal cubits divisible by 7, which is the least probable divisor to produce a whole number, given that 7 is a prime number.
The size of the pyramid was now determined by choosing h. The first seked pyramids (Khufu’s Great Pyramid and stage 3 of the pyramid at Meidum) kept the mastaba’s height (h) at the familiar 20 Rc (or 2 x 20 Rc for the Great Pyramid). However, based on the division of the pyramid into 7, it was now possible to choose different heights as long as the main measurements of H, B, and A were in whole Royal cubits. To divide these measurements by 7 is straightforward: b is the same number in palms as B is in Royal cubits and similarly a is the same number in palms as A is in Royal cubits (Fig. 76). This explains why the use of palms is present in the project documentation for the seked pyramid, while all numbers relating to the true pyramid are given in Royal cubits.
This system enabled the Egyptians to vary H but still keep full control over the parameters of the pyramid. All that was necessary was to start by choosing h and keep d at ¼ h, and then numerous measurement points could be determined throughout the volume of the pyramid. This change in project method is the reason why I differentiate between true pyramids and seked pyramids, whereas other scholars have categorized seked pyramids under true pyramids.