Assuming that the side length of a right angle is X and the other side is Y, then the area is 1/2xy = 4, then the third side of the triangle with xy = 8 can be known as X plus Y under the heel sign by Pythagorean theorem, and then X plus Y under the heel sign with the circumference of X+y+ passes the mean inequality. Under this formula > = 2*XY+2* heel sign, xy = 4+4 times heel sign 2, only if X =