Pythagoras was the religious philosopher and mathematician who interpreted the world through numbers. Little is known about his life and no writings by him survive, but it is known that he and his followers had considerable influence in the scientific and political communities of the time. Pythagoreans developed many areas of mathematics and science very rapidly, exploring numbers using pebbles and arranging them into lines, squares and triangles (the Greek word for pebble is 'calculus', from which the modern word to calculate is derived). The Pythagoreans were the first to discover that the square root of two is an irrational number, and it is said that one of their members was murdered for divulging this information to others.
Pythagoras was probably the discoverer of the familiar result named after him, stating that the square of the hypotenuse of a right-angled triangle is equal to the sum of the squares of the other two sides. He realized that the sum of the angles in a regular triangle is equal to two right angles and also determined the main intervals in the musical scale. His life is shrouded by stories and myths, but it can be said that the work of Pythagoras and his followers was profoundly influential among subsequent generations of philosophers, astronomers and mathematicians.
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