Pythagoras

Pythagoras was a Greek thinker and religious teacher who lived around 570–495 BCE. He was born on the island of Samos, in the eastern Aegean, and later settled in Croton, a Greek city in southern Italy. There he founded a community whose members combined religious practices with the study of mathematics, music, astronomy, and philosophy.

Much of what we know about Pythagoras comes from writers who lived centuries after him, so it is difficult to separate his own ideas from those later attributed to him. He apparently did not leave written works, and details of his life are surrounded by tradition and legend. Pythagoras is best known today for the theorem that bears his name.

In a right-angled triangle, the square of the longest side, called the hypotenuse, equals the sum of the squares of the other two sides: a² + b² = c². The theorem was known in some form before Pythagoras, including in ancient Babylonian mathematics, and there is no solid evidence that he personally discovered it.

What became known as the Pythagorean tradition helped make mathematical reasoning an important part of Greek intellectual life. Pythagorean thinkers also explored numerical relationships in music and studied the heavens, linking mathematics with ideas about order and harmony.