In 1940, the British aviator performed Cairo shooting and the adjoining Gizzard platforms. He managed to take a photo of the Great Pyramid, from which it was evident that the pyramid had 8 walls. So, each wall is divided into half in its axis.

The walls are concave (curved inwards) by approximately 0,5 ° to 1 °. This phenomenon is observable mainly from the air. An observer on earth sees the phenomenon only for a very short time a few seconds during the equinox. At that moment, the Sun illuminates the pyramid so that half of the wall is in shadow and the other half is brightly lit.

It follows from the whole phenomenon that the architects of the building had to be very familiar with mathematics and astronomy. This action requires very precise planning and focus of the construction.

It is also worth mentioning the fact that the Great Pyramid is currently the only one known to have such a structure.