Bryson of Heraclea (ca. 450 BCE  ca. 390 BCE) was an ancient Greek mathematician and sophist who contributed to solving the problem of squaring the circle and calculating pi.
Contents 
Although little is known about the life of Bryson, it is believed that he was probably a pupil of Socrates. He is said to have upset Aristotle by asserting that obscene language does not exist.
Bryson, along with his contemporary Antiphon, was the first to inscribe a polygon inside a circle, find the polygon's area, double the number of sides of the polygon, and repeat the process, resulting in a lower bound approximation of the area of a circle. "Sooner or later (they figured), ...[there would be] so many sides that the polygon ...[would] be a circle" (Blatner, 16). Bryson later followed the same procedure for polygons circumscribing a circle, resulting in an upper bound approximation of the area of a circle. With these calculations Bryson was able to approximate π and further place lower and upper bounds on π's true value. But due to the complexity of the method, he only calculated π to a few digits. Aristotle criticized this method, but Archimedes would later use a method similar to that of Bryson and Antiphon to calculate π; however, Archimedes calculated the perimeter of a polygon instead of the area.

