Pappus of Alexandria was a late Greek geometer whose theorems provided a foundation for modern projective geometry. Virtually nothing is known about his life. He wrote his major work, Synagoge, or the Mathematical Collection, as a guide to Greek geometry. This collection of mathematical writings in eight books is thought to have been written around 340, although some historians believe that Pappus had completed the work by 325. Pappus' work discusses the theorems of more than thirty different mathematicians of antiquity,