Back Euklidiese meetkunde AF ዩክሊዳዊ ጂዎሜትሪ AM هندسة إقليدية Arabic Xeometría euclídea AST Evklid həndəsəsi AZ Евклид геометрияһы BA Euclidean geometry BCL Эўклідава геаметрыя BE Эўклідава геамэтрыя BE-X-OLD Евклидова геометрия Bulgarian
Euclidean geometry is a system in mathematics. People think Euclid was the first person who described it; therefore, it bears his name. He first described it in his textbook Elements. The book was the first systematic discussion of geometry as it was known at the time. In the book, Euclid first assumes a few axioms. These form the base for later work. They are intuitively clear. Starting from those axioms, other theorems can be proven.
In the 19th century, other forms of geometry were discovered. These are usually dubbed non-Euclidean geometries. Carl Friedrich Gauss, János Bolyai, and Nikolai Ivanovich Lobachevsky were a few people that (independently of eachother) developed such geometries. Very often, these do not use the parallel postulate, but the other four axioms.