(PHP 4 >= 4.0.7, PHP 5)
hypot — Calculate the length of the hypotenuse of a right-angle triangle
hypot() returns the length of the hypotenuse of a right-angle triangle with sides of length x and y , or the distance of the point (x , y ) from the origin. This is equivalent to sqrt(x*x + y*y).
Length of first side
Length of second side
Calculated length of the hypotenuse