Know some interesting facts about Great Pyramid of Egypt

New Delhi: The Great Pyramid of Egypt - Giza is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact. Here Egyptologists believe that the pyramid was built as a tomb for fourth dynasty Egyptian Pharaoh Khufu (Cheops in Greek) over a 10 to 20-year period concluding around 2560 BCE. Initially at 146.5 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for over 3,800 years. Here are some interestinn facts about this wonderfull structure: The pyramid is estimated to have about 2,300,000 stone blocks weighing from 2-30 Tons each with some weighing as much as 70 tons.Two types of limestone were used for construction. A soft limestone either pure or nummulitic was used for the bulk of the core blocks and a hard white limestone for the mantle. Hard limestone becomes more polished with age. There is so much stone mass in the pyramid that the interior temperature is constant and equals the average temperature of the earth, 20 Degrees Celsius (68 Degrees Fahrenheit). The base of the pyramid covers 55,000m2 (592,000 ft2) with each side greater than 20,000m2 (218,000 ft2) in area.The outer mantle was composed of 144,000 casing stones, all highly polished and flat to an accuracy of 1/100th of an inch, about 100 inches thick and weighing about 15 tons each.The average casing stone on the lowest level was 5 ft. long by 5 ft. high by 6 ft. deep and weighed 15 tons.The mortar used is of an unknown origin. It has been analyzed and its chemical composition is known but it can't be reproduced. It is stronger than the stone and still holding up today.The relationship between Pi (p) and Phi (F) is expressed in the fundamental proportions of the Great Pyramid. Aligned True North: The Great Pyramid is the most accurately aligned structure in existence and faces true north with only 3/60th of a degree of error. The position of the North Pole moves over time and the pyramid was exactly aligned at one time. Centre of Land Mass: The Great Pyramid is located at the centre of the land mass of the earth. The east/west parallel that crosses the most land and the north/south meridian that crosses the most land intersect in two places on the earth, one in the ocean and the other at the Great Pyramid.