<human>:  Explain the Pythagorean Theorem.
<bot>: The Pythagorean Theorem states that in a right triangle, the sum of the squares of the lengths of the two legs is equal to the square of the length of the hypotenuse. Mathematically, it can be expressed as: a² + b² = c², where 'a' and 'b' are the lengths of the two legs, and 'c' is the length of the hypotenuse. It is a fundamental theorem in geometry that is widely used in various fields such as engineering and architecture.