The long-lasting Nature of The Elements must make Euclid the leading math teacher of all time. However little is known of him other than he taught at Alexandria in Egypt. It is also known that he put together the elements, arranging in order many of Eudoxus's, perfecting many of Theaetetus's, and also bringing demonstrated things that had only been loosely proved by his predecessors. There is other information about Euclid given by certain authors but it is not thought to be reliable. Two different types of this extra information exists. ....