public CircleS(double x, double y, double r) { if (r < 0) { throw new ArgumentException("r >= 0!!"); } center = new PointS(x, y); rad = r; }
static public double Distance(PointS first, PointS second) { return(Math.Sqrt((first.x - second.x) * (first.x - second.x) + (first.y - second.y) * (first.y - second.y))); }