It is hard to imagine that the ordinary geometric system we are studying now was founded by the ancient Greek mathematician Euclid in 300 BC. From then until now, in the long history of more than 2,000 years, his Elements of Geometry has always been regarded as a standard textbook for learning geometry.

Euclid was born in Megara, Greece about 330 BC and died in 275 BC. In his early years, he studied at Plato's Academy in Athens, and he was very proficient in mathematics, astronomy and Plato's theory and became a famous scholar at that time. At the age of about 30, he came to Alexandria at the invitation of King Ptolemy and settled there.

Alexandria was the political and cultural center of Greece at that time, which attracted a large number of scholars to study here. Euclid made use of this advantage to meet many profound scholars, who exchanged research results and ideas with each other. This broadens Euclid's thoughts and accumulates rich materials for his writing Elements of Geometry.

Ancient Greek philosophers studied mathematics for a long time. Euclid has published some works about geometry before, but all of them discuss a certain aspect, and the content is not systematic enough. Based on the achievements of mathematicians in early ancient Greece, Euclid's Elements of Geometry was published around 300 BC, and the geometric structure system established by this work marked that geometry became an independent discipline. At the same time, this work is also the inheritance and innovation of Euclid's achievements in Greek geometry since the 7th century BC, which has a far-reaching impact on the development of mathematics, science and other disciplines and the whole thinking method of westerners.

Originally written in Greek, The Elements of Geometry has been widely circulated as a textbook for more than 2,000 years. It is said that it has reached more than 1000 versions now. This book has had an immeasurable influence on later generations. Many scientists tried to imitate Euclid, trying to logically deduce all their conclusions from several primitive conditions. The most prominent one is isaac newton, whose magnum opus Mathematical Principles of Natural Philosophy is written in a form similar to Geometry Elements.

In addition to the Elements of Geometry, Euclid also wrote books such as Data and Graph Segmentation, Wrong Conclusions about Mathematics, Optics and Reflective Optics. Among them, the incident angle and reflection angle are studied optically, and the conclusion that they are equal is obtained, that is, the original law of light reflection.

As a rigorous scholar and a moderate educator, Euclid opposed anyone's opportunism in learning and the pursuit of fame and fortune. Although Euclid made a lot of efforts in simplifying geometry, King Ptolemy, as his student, still could not understand it. So king Ptolemy asked Euclid for advice: Is there a shortcut to learning geometry?

Euclid replied, "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.