History of geometry lost. He was brought to the university at Alexandria by Ptolemy I, King of Egypt. "The Elements" began with definitions of terms, fundamental geometric principles (called "axioms" or "postulates"), and general quantitative principles (called "common notions") from which all the rest of geometry could be logically deduced. Following are his five axioms, somewhat paraphrased to make the English easier to read. Concepts, that are now understood as algebra, were expressed geometrically by Euclid, a method referred to as Greek geometric algebra. Archimedes (287-212 BC), of Syracuse, Sicily, when it was a Greek city-state, is often considered to be the greatest
Lighthouse of Alexandria Lighthouse of Alexandria The Lighthouse of Alexandria, sometimes called the Pharos of Alexandria (; Ancient Greek: ὁ Φάρος τῆς Ἀλεξανδρείας, contemporary Koine ), was a lighthouse built by the Ptolemaic Kingdom, during the reign Ptolemy II Philadelphus (280–247 BC) which has been estimated to be in overall height. One of the Seven Wonders of the Ancient World, for many centuries it was one of the tallest man-made structures in the world. Badly damaged by three earthquakes between AD 956 and 1323, it then became an abandoned ruin. It was the third longest surviving ancient wonder (after the Mausoleum at Halicarnassus