Pythagoras Theorem : This article explains the concept of Pythagoras Theorem and its converse. Know the definition, formula , proof, examples and applications of Pythagoras Theorem . Pythagoras Theorem – Define, Formula and Solved Example Pythagoras theorem states that “In a right-angled triangle, the square of the hypotenuse side is equal to the sum of squares of the other two sides (base and perpendicular)”. Pythagorean Theorem Calculator uses the Pythagorean formula to find hypotenuse c, side a, side b, and area of a right triangle. Pythagorean triples explained. Learn the Pythagorean theorem , a fundamental relation in Euclidean geometry between the three sides of a right triangle. See different proofs, generalizations, and applications of the theorem .