Question: Which geometrical theorem is a fundamental relation in Euclidean geometry involving the longest side of a right-angled triangle?
Sentence (from "Hypotenuse"): The length of the hypotenuse of a right triangle can be found using the Pythagorean theorem, which states that the square of the length of the hypotenuse equals the sum of the squares of the lengths of the other two sides.
Relevant evidence: No