The Pythagorean theorem is a fundamental principle in geometry that relates to right triangles. It states that in a right 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 with the formula: a^2 + b^2 = c^2 , where c represents the hypotenuse, and a and b are the other two sides. This theorem is named after the ancient Greek mathematician Pythagoras, who is credited with its discovery, although it was known to other cultures before him. The Pythagorean theorem is widely used in various fields, including architecture, engineering, and physics, to calculate distances and relationships between different points in space.