勾股定理, also known as the Pythagorean theorem, is a fundamental principle in geometry. 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 mathematically as a^2 + b^2 = c^2 , where c is the hypotenuse and a and b are the other two sides. This theorem is named after the ancient Greek mathematician 毕达哥拉斯 (Pythagoras), who is credited with its discovery. The theorem is widely used in various fields, including architecture, engineering, and physics, to calculate distances and relationships between different geometric shapes. Understanding 勾股定理 is essential for solving many practical problems involving right triangles.