This is the prototype for the non-stepped style of pyramids in Egypt. Lower part has a much higher inclination than the upper part (54° vs 43°) and it's thought that half way through construction a correction was made to the angle for stability. This second angle is the one used for every other pyramid built afterwards. Interestingly this 43° angle is achieved when the perimeter distance of the base of the pyramid is almost exactly 2π multiplied by its height. To put it another way, if the square base was deformed into a circle with the circumference equal to the sum of the original four sides, then the radius of this circle would equal the height of the pyramid.

Sneferu, the king who commissioned this pyramid, is the father of Khufu who built the Great Pyramid at Giza.