The Pythagorean theorem is a fundamental principle in mathematics that relates to right triangles. Formulated by the ancient Greek mathematician Pythagoras, 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 theorem is expressed mathematically as a² + b² = c². Its significance extends beyond geometry; it is essential in fields such as physics, engineering, architecture, and computer science, aiding in calculations involving distance, angles, and spatial relationships.