Based on Keith Hamilton's guides on the Red pyramid and the Bent pyramid I was looking into the design of the pyramid slope of the three pyramids at Dahshur. That is the slope of the two large pyramids as also the slope of the Bent cult pyramid. What was the plan? Did astronomic factor weigh in? Using my Stellarium astronomy software I was able to come up with a simple explanation as to how the specific angles were chosen. The lower part of the lower slope of the Bent pyramid was chosen so as to align with the altitude at upper culmination (alignment with the Southern Meridian: 180 degrees azimuth), of a specific celestial body. This could be a star, a planet, the Sun, the Moon, it makes no difference.


At the same time the South - East and South - West directions of 135 and 225 degrees azimuth respectively we meant to determine the altitude of this specific celestial body so as to plan the slope of the Red pyramid as also that of the Bent cult pyramid. In the image below I used the geographical coordinates of these 3 pyramids.





It seems like the smooth sided pyramid idea that materialized during Sneferu's rule relates to the square base diagonals that define the South-East, and South-West directions(45 degree division).