Actually, there aren't four: scientists reveal how many sides the Great Pyramid of Giza truly has (photo).

The Egyptian Pyramids are among the most renowned monuments of ancient Egyptian art. While much is known about them, there remains a great deal to uncover: for instance, the contents of the void sealed within the Great Pyramid of Giza, which is at least 4,500 years old, and the methods used to transport the materials for its construction to this area, as reported by IFLScience.

Equally intriguing is the question of how many sides the Great Pyramid of Giza has, which is also regarded as the primary pyramid of Egypt. One might assume there are four, but that is incorrect. Some also suggest that the Great Pyramid has three or five sides, but this assumption is also far from the truth.

The exact number of sides has not been officially confirmed, at least by modern standards, until British Air Force pilot P. Groves photographed the pyramid from above in 1926. From this perspective, scholars observed that the sides of the pyramid are actually significantly concave along their midlines.

According to Ayo Kato from the Department of Mathematics and Physics at Kanagawa University in Japan, it has been revealed that the Great Pyramid of Giza exhibits a remarkable concavity, as each of its four faces is concave along its central line—from the base to the apex.

In simple terms, the Great Pyramid is a concave octagonal pyramid rather than a standard square one. This concavity is too subtle to be noticed from the ground, which is why it went unnoticed until the pyramid was photographed from space.

Researchers are not entirely sure, but they suspect that these concavities likely contribute to the pyramids' stability and longevity. According to Kato, the sloped layers combined with a reinforced base are essential for the pyramid's stability against natural forces such as gravitational compression, earthquakes, or heavy rains. Scientists now theorize that these structures are what have enabled the Great Pyramid of Giza to endure an astonishing 4,500 years.

A crucial aspect of stability is that the impact of such natural forces varies significantly between the core of the sloped and truly flat rows. The former can be compacted over time, becoming even stronger, while the flat ones would deteriorate and weaken over time.

It is well-known that the ancient Egyptians were skilled engineers, as evidenced by the pyramids that still exist today. However, several sealed corridors and chambers within the pyramid may have been abandoned by the builders due to their instability. This brings us back to the question of whether the additional sides of the Great Pyramid were a deliberate design choice for durability or merely a coincidence.