The geometry we are studying now was founded by the ancient Greek mathematician Euclid (330 BC-275 BC). The Elements of Geometry, written by him in 300 BC, has been regarded as the standard textbook for studying geometry for more than 2,000 years, so Euclid is called the father of geometry.

Born in Athens, Euclid accepted Greek classical mathematics and various scientific cultures and became a famous scholar at the age of 30. At the invitation of the king of Egypt, he stayed in Alexandria to teach and do research.

Mathematics research in ancient Greece has a very long history, and there have been some works on geometry, but all of them discuss a certain aspect and the content is not systematic enough. Euclid collected predecessors' achievements and adopted an unprecedented and unique writing method. First, he put forward definitions, axioms and postulates, then proved a series of theorems from simple to complex, and discussed plane figures and three-dimensional figures, as well as integers, fractions and proportions. , finally completed the masterpiece "Geometry".

After the publication of the original, its manuscript has been circulated for 1800 years. After 1482 was printed and published, it was reprinted about 1000 times, and it was also translated into major languages in the world. /kloc-was introduced to China in the 3rd century and soon lost. The first six volumes were retranslated in 1607, and the last nine volumes were retranslated in 1857.

Euclid was good at solving complex problems with simple methods. He measured the length of the shadow of the pyramid at the moment when the figure of a person was just equal to the height, and solved the big problem of the height of the pyramid that no one could solve at that time. He said: "At this time, the length of the tower shadow is the height of the pyramid."

Euclid was a gentle and honest educator. Euclid was also a rigorous scholar. He opposes opportunism and the pursuit of fame and fortune in his studies, and the style of opportunism and quick success. Although Euclid simplified his geometry, the king (Ptolemy) still didn't understand and wanted to find a shortcut to learn geometry. Euclid said: "In geometry, everyone can only take one road, and there is no paved road for the king." This sentence has become an eternal learning motto. Once, one of his students asked him, what are the benefits of studying geometry? He said humorously to his servant, "Give him three coins because he wants to get real benefits from his study."

Euclid also wrote the known number and division of numbers.