Flagship interactive exemplar

Giza: one slope, three readings

A dynamic comparison of the Great Pyramid's 5½-palm seked with the famous pi and phi interpretations generated by the same triangle.

One base, three height rules

Compare what each reading actually changes.

The base remains fixed at 440 royal cubits. Each model asks what height would make one rule exact, then compares that ideal with the conventional 280-cubit reference.

True-scale Great Pyramid profile comparisonA true-scale cross-section with a 440-cubit base and a height close to 280 cubits. The selected ideal and reference profile almost completely overlap.BASE 440 ROYAL CUBITS280 cubits
True-scale cross-section. The differences are so small that the selected gold profile and the dashed 280-cubit reference overlap at this scale.
Historically grounded model

Selected height rule

5½-palm seked

280royal cubits high

A 5½-palm horizontal run for each royal cubit of rise gives the 14:11 profile.

Matches the 280-cubit reference exactly in this conventional model.

Reference profile440 base × 280 height
Choose a height rule
Historically grounded model

5½-palm seked

Seven palms of rise for 5½ palms of run produces the exact 14:11 triangle in the conventional cubit model.

Model variance: 0%
Interpretation

Pi comparison

For 440 by 280 cubits, perimeter divided by height is 44/7. This is close to 2π.

Variance: 0.0403%
Interpretation

Phi comparison

Slant height divided by half-base is close to φ, producing a near Kepler triangle.

Variance: 0.0344%

The central finding

The three results are mathematically dependent.

The standard 440-by-280-cubit model produces a half-base of 220 and a height of 280. Reduce that triangle and the rise-to-run ratio is 14:11. The seked is therefore 5½ palms. Perimeter divided by height becomes 44/7, close to 2π. The slant ratio becomes close to φ.

Those are not three independent codes discovered in separate parts of the monument. They are three descriptions of one slope. A deliberate 5½-palm construction choice could create both modern comparisons without the architect selecting π and φ as abstract targets.

Interpretive boundaryThe numerical closeness is measured. Claims about what Khufu's designers intended are interpretations. No surviving Fourth Dynasty design text names π, φ, or a Kepler triangle.

What the evidence can support

Petrie's survey supports careful reconstruction of the monument. The royal-cubit system is supported by physical rods and architectural analysis. Egyptian seked mathematics is documented in the later Rhind Mathematical Papyrus. Together they make a practical slope model historically plausible while leaving intention open.

Read the monument dossier · Test the 440 × 280 model · Use the sacred-geometry evidence framework