In case you've ever wondered, the Egyptians did not use the number pi when constructing the pyramids. The only pyramid that comes remotely close is Khufu. It was a tried and tested method of how high a pyramid could be built with the least amount of ground area. Khufu was 11 cubits high for every 3.5 across, or 22/7. The Egyptians did, however, utilize simple machines to great effect to construct their pyramids.
Of the seven wonders of the world noted in the Antipater of Sidon in the second century BC, only the the oldest of the seven remain - the Pyramids of Egypt. The other six are: The Hanging Gardens of Babylon, the Statue of Zeus at Olympia, the Temple of Artemis at Ephesus, the Mausoleum at Halicarnassus, the Colossus of Rhodes, and the Pharos at Alexandria.
Tours are offered to the Giza site daily. If you plan on seeing the pyramids and want to go on a guided tour, be sure that the price includes both ways, and that the entrance to the pyramids, especially the Cheops pyramid, is included in the price.
The Great Pyramid at Giza, Egypt
The Great Pyramid at Giza, Egypt stands almost exactly on the 30th parallel at latitude 29 degrees, 58 minutes, 51 seconds1. If the Pyramid was intended to stand exactly on the 30th parallel, then this is an astonishing level of accuracy.
But what if the ancient Egyptians had intended it to be slightly askew? There is a theory that if a man stood at the base of the Great Pyramid and wished to see the pole of the sky, then a slight correction would be necessary in order to counteract the effects of the curvature of the Earth's surface. Rather than standing exactly on the 30th parallel, the pyramid would need to be sited at 29 degrees, 58 minutes, 22 seconds. If this is true, then it means the true error of accuracy is just 29 arc seconds or 29 sixtieths of one sixtieth of one degree!
The four sides of the pyramid are aligned with the four cardinal points of the compass. On average, the deviation from true is three arc minutes. A difference of three degrees would go unnoticed by the naked eye, but the Egyptians went for greater accuracy in the alignment of the sides. The north/south axis of the pyramid is offset from true north by three-sixtieths of a degree. By contrast, the Meridian Building at London's Greenwich Observatory is offset by nine-sixtieths.
The four sides of the pyramid measure, on average, just over 9063 inches. The north side is 755 feet, 4.9818 inches in length; the south side 756 feet, 0.9739 inches; the east 755 feet, 10.4937 inches and the west 755 feet, 9.1551 inches. The difference between the longest and shortest sides is slightly less than eight inches. The base of the pyramid therefore covers over 13 acres.
The corners of the pyramid are not quite true right angles, but again are impressively close. On a normal modern building, the corners can be over a degree from true - it doesn't affect the building structurally, and is not visibly obvious. On the Great Pyramid, the four corners are far, far closer. The north-eastern corner is 90 degrees, 3 minutes, 2 seconds; the south-eastern corner is 89 degrees, 56 minutes, 27 seconds; the south-western corner is 90 degrees, 33 seconds, whilst the north-western corner is an incredible 89 degrees, 59 minutes, 58 seconds, just two arc seconds from being a true right angle.
It is estimated that the pyramid consists of 2.3 million limestone and granite blocks. Of these, tens of thousands have been estimated to weigh over 15 tons each, with the average sized blocks weighing around 2.5 tons - more than twice the weight of the average family car. Engineering logic and common sense dictate that the larger blocks would be at the base of the pyramid, and after that the weight and size of the blocks would decrease. To begin with, the pyramid does follow this mode of thought. But this only holds true for so long, the first 18 courses to be exact. Course 19 jumps to being in the 15 ton range, from the 2.5 ton blocks below. By course 19 you are already over 100 feet up. The Great Pyramid consists of 203 separate courses, with an average height from one course to the next being 30 inches. The 203rd course consists of several hundred blocks weighing around five tons each, and by this time the height is over 450 feet.
It has been estimated that the Great Pyramid weighs about six million tons. Its original weight would have been greater, as the pyramid was once covered by 115,000 highly polished facing stones weighing approximately 10 tons each. Unfortunately, the majority of these had been shaken loose in a massive earthquake in 1301 AD, and were carted off by the natives for use in buildings in Cairo.
It was once calculated by a man with a growing obsession for personal privacy that there is enough stone in the Great Pyramid of Gizeh to build a wall 10 feet high, and 1 foot thick, around the entire border of France.
He was denied planning permission.