Believed to have been built for the Pharaoh Khufu over a 20-year period, the colossal monument still stands as the oldest and largest of the three ancient pyramids on the Giza Plateau. Among the Seven Wonders of the Ancient World, it is the only one still largely intact and is estimated to weigh approximately six million tonnes, from the 2.3 million blocks of limestone and granite used, some weighing as much as 80 tonnes. There have been varying theories about the Great Pyramid’s construction techniques, but most accepted hypotheses are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.
When the work was finished, the pyramid was encased in white limestone, which in the years since has been stripped away, likely to be used for other projects.
But when researchers from US-based Glen Dash Research Foundation and the Ancient Egypt Research Associates (AERA) were studying what the original structure would have looked like, they identified a “flaw” in the work.
Head of the foundation, Glen Dash, said: “Most of those casing stones were removed centuries ago for building material, leaving the pyramid as we see it today, without most of its original shell.”
The team identified 84 points on the pyramid where the outer stones were likely positioned by searching for markings on the remaining structure.
These points were plotted on a grid so that the researchers could use a technique called linear regression to calculate the lengths of each side.
They found that three sides of the pyramid were once between 230.295 metres and 230.373 metres long, but the west side came in between 230.378 metres and 230.436 metres – meaning it was off by about 14.1cm.
This led the team to theorise that “the base is not quite square,” but, despite this, they were still baffled over how the ancient workers came so close to perfection.
Mr Dash, who passed away in 2019, added: “The data shows that the Egyptians possessed quite remarkable skills for their time.
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The 2015 report concluded: “Our survey has produced new estimates for the size and orientation of the Great Pyramid.
“We also continue to analyse the data for new insights, and we have not been disappointed.
“We hope to eventually figure out how the Egyptians laid out the pyramid with such precision, and in doing so hope to learn much about the tools and technology they had at their disposal.”