In China, the property that the sum of squares of two right angles of a right triangle is equal to the square of the hypotenuse is called Pythagorean theorem or Pythagorean theorem. Mathematical formulas are often written as A 2+B 2 = C 2.

Pythagorean theorem is a special case of cosine theorem. This theorem is also called "the High Theorem" in China (it is said that Dayu will use this theorem to solve the calculation problems in water conservancy), and it is called "Pythagoras Theorem" or "Hundred Cows Theorem" abroad. (After Pythagoras discovered this theorem, he beheaded a hundred cows to celebrate, so it was also called the "hundred cows theorem"), and the French and Belgians also called this theorem the "donkey bridge theorem" (