public double tinhKhoangCach(DiemOxy A)
{
double kc1, kc2, kc;
kc1 = Math.Pow(this.x - A.x, 2);
kc2 = Math.Pow(this.y - A.y, 2);
kc = 1.0 * Math.Sqrt(kc1 + kc2);
return(kc);
}
public DiemOxy(DiemOxy a)
{
this.x = a.x;
this.y = a.y;
}