public interface IShape 

{

    double height

    {

        get;

        set;

    }

    double width

    {

        get;

        set;

    }

    double area

    {

        get;

        set;

    }

}

​

class Rectangle : IShape

{

private double Height;

public double height

{

    get

    {

    return Height;

    }

    set

    {

    Height = value;

    }

}

private double Width;

public double width

{

    get

    {

    return Width;

    }

    set

    {

    Width = value;

    }

}

private double Area;

public double area

{

    get

    {

    return Area = height*width;

    }

    set

    {

    Area = value;

    }

}

}

​

public class Shape

{

    public static void Main()

    {

    Rectangle r = new Rectangle();

    System.Console.Write("Enter height: ");

    r.height = double.Parse(System.Console.ReadLine());

    System.Console.Write("Enter width: ");

    r.width = double.Parse(System.Console.ReadLine());

        System.Console.WriteLine("Area: {0}", r.area);

}

}

​