//Method used to calcualte and display the results
public static void Calculate(Shape1 S)
{
Console.WriteLine("Area : {0}", S.Area());
Console.WriteLine("Circumference : {0}", S.Circumference());
}
public static void Calculate(Shape1 S)
{
Console.WriteLine("Area: {0}", S.Area());
Console.WriteLine("Circumference : {0}", S.Circumference());
}