Euclid They follow the same logical structure as "Elements", with definitions and proved propositions. Other works are credibly attributed to Euclid, but have been lost. The European Space Agency's (ESA) Euclid spacecraft was named in his honor. Euclid Euclid (; – "Eukleídēs", ; fl. 300 BC), sometimes given the name Euclid of Alexandria to distinguish him from Euclides of Megara, was a Greek mathematician, often referred to as the "founder of geometry" or the "father of geometry". He was active in Alexandria during the reign of Ptolemy I (323–283 BC). His "Elements" is one of the most influential works in 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