A right triangle with sides equal to 3 and 4 cm has a hypotenuse of 5 cm

Explanation

Based on the Pythagorean theorem, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides. In this case, 5²=4²+3² (25=16+9). This is the simplest Pythagorean triple, and scaling it (6-8-10, 9-12-15...) produces endless right triangles.