//----------------------------------
static void Main(string[] args)
{
double x = 0, y = 0, r = 0;
Console.WriteLine("To input co-ordinate:");
Input(ref x, ref y);
try
{
do
{
Console.Write("To input r: ");
r = double.Parse(Console.ReadLine());
} while (r < 0);
}
catch (Exception e) { Console.WriteLine(e); }
Cycle c = new Cycle(x, y, r);
c.View();
Console.Write("Chu vi: {0:F3}\nDien tich: {1:F3}\nKhoang cach tam giac den goc toa do: {2:F3}\n", c.Circumference(), c.Area(), c.Line());
Console.ReadKey();
}