First completed true pyramid

Red Pyramid

Sneferu's successful smooth pyramid uses a shallower profile and offers a strong control case after Meidum and the Bent Pyramid.

PeriodFourth Dynasty, c. 2590 BCE
PlaceDahshur, Egypt
Dimensions modelled220.00 m base; 105.00 m heightSeked reconstruction of a shallow slope
Pattern under reviewSlant ratio near √2; not near phi
Measured or reconstructed dimensionsCalculated geometryInterpretation labelled

Why this pyramid belongs in the collection

The Red Pyramid completes the developmental sequence associated with Sneferu. Its stable, shallow form is historically more important than whether a modern constant can be fitted to it.

What can be measured

With a representative 220 metre base and 105 metre height, the calculator returns a face angle near 44 degrees, a slant near 152.07 metres, and a seked near 7.33 palms. The envelope volume is about 1.69 million cubic metres.

The native or comparative measure

The relatively large seked records a greater horizontal run for each cubit of rise. That is a practical description of the noticeably shallower face and connects the monument to the design problem visible at the Bent Pyramid.

Calculate this monumentOpen Red Pyramid in the pyramid calculator. The shared tolerance and rounding rules make its result directly comparable with the other seven pyramids.

The pattern worth testing

The slant-to-half-base ratio falls within about 0.032 of the square root of two. The perimeter-to-height ratio is far from 2 pi. Numerical proximity is reported, but the construction sequence and slope choice remain the stronger historical explanation.

Interpretive limit

A tolerance test finds proximity, not intention. The square-root-of-two comparison would require independent textual, procedural, or repeated architectural evidence before it could become a historical claim.

A repeatable investigation

Begin with the published or reconstructed dimensions and state the shape assumption. Calculate the seked and ordinary geometry before testing a named constant. Keep the chosen broad ±0.5 exploratory screen fixed across the full collection, display the residual for every match, and treat a numerical result as evidence of intention only when independent historical evidence supports it.

Open the pyramid calculator · Read the seked guide · Return to Temples and sites