a variable point on a rectangle@@

@There is a variable point on a rectangle.Point P moves on rectangle ABCD( B->C ). Point of intersection(two gray lines) means area of triangle ABP. Move point P to find the quality between the area of triangle ABP and the length of locus(P). E-mail me @You can also move point P ,the numbers and top segment length (the length of unit)on CABRI. Download CABRI‡U data (d59) from here.