What formula did Pythagoras develop?

Pythagoras is best known for the Pythagorean theorem, which states that in a right-angled triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. This can be expressed mathematically as (a^2 + b^2 = c^2), where (c) represents the hypotenuse and (a) and (b) are the other two sides. This theorem is fundamental in geometry and has numerous applications in various fields, including mathematics, physics, and engineering.