Let the hypotenuse length be " H " cm Then the other leg of the triangle is= cm. The area of the triangle is half the product of the legs Area = . The area can be presented in other way as half the product of the hypotenuse and the perpendicular L drawn to the hypotenuse Area = . So, we have this equation = . From this equation, after canceling the factor in both sides, you get L = . It is the expression of the length of the altitude via the hypotenuse length. ANSWER. L = .