Euclid's Elements Euclid's Elements The Elements ( "Stoicheia") is a mathematical treatise consisting of 13 books attributed to the ancient Greek mathematician Euclid in Alexandria, Ptolemaic Egypt c. 300 BC. 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. "Elements" is the oldest extant large-scale deductive treatment of mathematics. It has proven instrumental in the development of logic and modern science, and its logical rigor was not surpassed until the 19th century. Euclid's "Elements" has been referred to as the
Reign of Cleopatra and introduced relief efforts such as releasing grain from the royal granary. Both Ptolemy XII and Cleopatra VII found it necessary to debase Ptolemaic coinage due to financial troubles. No gold coins are known from Cleopatra's reign, while use of bronze coins was revived (absent since the reign of Ptolemy IX) and silver currency was debased roughly 40% by the end of her reign. Coins struck under Cleopatra's reign came from a wide geographical expanse, including sites in Egypt like Alexandria, but also the island of Cyprus, Antioch, Damascus and Chalcis ad Belum in Syria, Tripolis in Phoenicia, Askalon in