from base to peak," Kato wrote. "In other words, the Great Pyramid is a concave octagonal pyramid, rather than the standard square pyramid. This concavity is so subtle to be seen from any ground ...

from base to peak," he wrote. "In other words, the Great Pyramid is a concave octagonal pyramid, rather than the standard square pyramid," he added. This intriguing characteristic of the Great ...

The Great Pyramid of Giza, thought to have four sides ... Despite being visible for centuries, the octagonal design wasn’t widely discussed until aerial photography captured its concavity ...