Pythagoras often receives credit for the discovery of a method for calculating the measurements of triangles, which is known as the Pythagorean theorem. However, there is some debate as to his actual contribution the theorem.
Pythagoras was an Ionian Greek philosopher, mathematician and religious scholar. His greatest contribution to mathematics is the Pythagorean theorem. The theorem states that in a right triangle, the area of the square of the hypotenuse, which is the side across from the right angle, is equal to the sum of the square of the areas of the other two sides. Despite the theorem bearing his name, Pythagoras was not the first person to use this calculation. This computation was in use in Mesopotamia and India long before Pythagoras lived. There is some speculation that Pythagoras and his students are responsible for the first proof of the theorem. However, given that it was the nature of Pythagoras' students to attribute everything to their teacher, it is unclear if Pythagoras himself ever worked on the proof.
Besides mathematics, Pythagoras made contributions to religion and music. Pythagoras and his followers believed that souls did not die but went through a cycle of rebirth that ended when purity of life was obtained. Pythagoras' beliefs placed great emphasis on a lifelong search for salvation. Pythagoras might also be responsible for an understanding of string length in relation to tone in musical instruments.