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
Patriarch Peter VII of Alexandria Patriarch Peter VII of Alexandria Petros VII (September 3, 1949 – September 11, 2004) was the Greek Orthodox Pope and Patriarch of Alexandria and all Africa from 1997 to 2004. During his reign, Petros VII was credited with reviving the Greek Orthodox churches in Africa by increasing the churches' attendance of about 250,000 people. Petros was born Petros Papapetrou () in Sichari, Kyrenia District, Cyprus on September 3, 1949. He was the oldest son of a Greek Orthodox family and both his father and grandfather were priests. At the age of 12, Petros enrolled at the Machairas Monastery. Then at