What roman author described the technique of Opus quadratum?
Vitruvius Marcus Vitruvius Pollio (born c. 80–70 BC, died after c. 15 BC), commonly known as Vitruvius, was a Roman author, architect, civil engineer and military engineer during the 1st century BC, known for his multi-volume work entitled "De architectura". His discussion of perfect proportion in architecture and the human body, led to the famous Renaissance drawing by Da Vinci of "Vitruvian Man".
Ovid Publius Ovidius Naso (] ; 20 March 43 BC – AD 17/18), known as Ovid ( ) in the English-speaking world, was a Roman poet who lived during the reign of Augustus. He was a contemporary of the older Virgil and Horace, with whom he is often ranked as one of the three canonical poets of Latin literature. The Imperial scholar Quintilian considered him the last of the Latin love elegists. He enjoyed enormous popularity, but, in one of the mysteries of literary history, was sent by Augustus into exile in a remote province on the Black Sea, where he remained until his death. Ovid himself attributes his exile to "carmen et error", "a poem and a mistake", but his discretion in discussing the causes has resulted in much speculation among scholars.