Given a triangle with side lengths of a, b, and c, where c is the longest side, which statement is true?

The Pythagorean theorem says a triangle is a right triangle when the squares of its two shorter sides add up to the square of its longest side. Since c is the longest side, the condition is a² + b² = c². Therefore, the true statement is “If a² + b² = c², then the triangle is a right triangle.”

AI-written and checked against the verified answer.