Non-Euclidean geometry that are both perpendicular to a third line: Euclidean geometry, named after the Greek mathematician Euclid, includes some of the oldest known mathematics, and geometries that deviated from this were not widely accepted as legitimate until the 19th century. The debate that eventually led to the discovery of the non-Euclidean geometries began almost as soon as Euclid's work "Elements" was written. In the "Elements", Euclid began with a limited number of assumptions (23 definitions, five common notions, and five postulates) and sought to prove all the other results (propositions) in the work. The most notorious of the postulates is often
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