const
PIDiv180 = 0.017453292519943295769236907684886;

procedure Rotate(RotAng: Double; x, y: Double; var Nx, Ny: Double);
var
SinVal: Double;
CosVal: Double;
begin
RotAng := RotAng * PIDiv180;
SinVal := Sin(RotAng);
CosVal := Cos(RotAng);
Nx := x * CosVal - y * SinVal;
Ny := y * CosVal + x * SinVal;
end;
(* End Of Rotate Cartesian Point*)