Quartet

"Euclid (Ancient Greek: Εὐκλείδης Eukleidēs), fl. 300 BC, 
also known as Euclid of Alexandria, was a Greek
mathematician, often referred to as the 'Father of Geometry.'"

— Wikipedia

A Euclidean quartet (see today's previous post)—

Image by Alexander Soifer

See also a link from June 28, 2012, to a University Diaries  post
discussing "a perfection of thought."

Perfect means, among other things, completed .

See, for instance, the life of another Alexandrian who reportedly
died on the above date—

"Gabriel Georges Nahas was born in Alexandria, Egypt, on
 March 4, 1920…."

 — This afternoon's online New York Times