Elements by Euclid
The Elements (Greek: ฮฃฯฮฟฮนฯฮตแฟฮฑ Stoikheรฎa) is a mathematical treatise consisting of 13 books attributed to the ancient Greek mathematician Euclid.
It is a collection of definitions, postulates, propositions (theorems and constructions), and mathematical proofs of the propositions. The books cover plane and solid Euclidean geometry, elementary number theory, and incommensurable lines.