The Egyptian pyramids, which are famous for their history, have not only attracted countless tourists for hundreds of years with their majestic momentum, but also attracted scientists from all over the world because of their unique design and exquisite architecture. According to the largest pyramid of khufu calculation, it is found that its original height is 146.5m (it is still 137m due to damage), and each side of the foundation is 233m (now it is 227m). But the error of each base length is only 1.6 cm, which is only the whole length; The right angle error of the base is only 12 ",which is just a right angle. In addition, the four sides of the pyramid face southeast and northwest respectively, and the deviations between the two sides of the bottom square and true north are only 2' 30 "and 5' 30" respectively.

Such a high pyramid was built with such precision that scientists were sure that the ancient Egyptians had a wealth of knowledge. This conjecture was confirmed when scientists deciphered the words on the grass clippings handed down by the ancient Egyptians.

It turns out that in the Nile Delta, there is an aquatic plant-papyrus, which is shaped like a reed. The ancient Egyptians cut the grass into small strips from the longitudinal plane, arranged it neatly, connected it into one piece, squeezed it out and dried it for writing. The words written on papyrus are called papyrus. Now sort out a part of this papyrus.

1822, a Frenchman named Gao made their meaning clear, making people know that the ancient Egyptians had learned to use mathematics to manage state and religious affairs, determine the remuneration paid to laborers, find out the volume of barns and the area of fields, estimate the local taxes that should be levied according to the land area, and calculate the number of bricks needed for building houses and defense projects; Calculate the amount of grain needed for brewing a certain amount of wine; Wait a minute. In the language of mathematics, the ancient Egyptians have mastered the operation of addition, subtraction, multiplication and division, as well as the operation of fractions; They solved one-dimensional linear equations and a special problem equivalent to binary quadratic equations. There are also questions about arithmetic progression and geometric series on papyrus. They calculated the area of rectangle, triangle and trapezoid, the volume of cuboid, cylinder and frustum, and the results were close to the modern calculation values. What is even more surprising is that they use the formula A=(d)2(d is the diameter) to calculate the circular area, which is equivalent to taking the π value as 3. 1605, which is very remarkable.

With such mathematical knowledge, it is not surprising that the ancient Egyptians built pyramids.