Theon of Alexandria, was a Greek scholar and mathematician who lived in Alexandria, Egypt, his daughter was Hypatia, a Greek mathematician, astronomer, inventor, and philosopher in Egypt, then a part of which location?
Theon of Alexandria Theon of Alexandria ( ; Ancient Greek: Θέων ὁ Ἀλεξανδρεύς ; c. AD  335 – c. 405) was a Greek scholar and mathematician who lived in Alexandria, Egypt. He edited and arranged Euclid's "Elements" and wrote commentaries on works by Euclid and Ptolemy. His daughter Hypatia also won fame as a mathematician.
Stone Tower (Ptolemy) Ptolemy, the Greco-Egyptian geographer of Alexandria, wrote about a "Stone Tower" (λίθινος πύργος in Greek, "Turris Lapidea" in Latin) which marked the mid-point on the ancient Silk Road – the network of overland trade routes taken by caravans between Europe and Asia. It was the most important landmark on this route, where caravans stopped on their difficult and dangerous journeys to allow travellers to take on provisions, rest, and trade goods before continuing on.