using System;

// 1. Create an interface IShape

public interface IShape 

{

    string Name {get; set;}

    double CalculateArea();

}

​

public interface IColor

{

    string Color {get; set;}

    bool IsYellow();

}

​

​

​

​

​

public class Triangle : IShape, IColor 

{

    private string _Name;

    public string Name 

    {

        get 

        {

            return _Name;

        }

        set

        {

            if (value.Length > 0) _Name = value;

            else Console.WriteLine("Please enter a name");

        }

    }

​

​

public string Color {get;set;} 

​

public double Base{ get; set;} 

public double Height {get; set;} 

​

​

​

    // [Code] 3.2 Create a private field and a public property for Name variable.

    //        The length of name should be more than 0. If length is zero,

    //        issue a warning and to not change the current value.

    //        (Hint: use Length property of a string.)

​

    // [Code] 3.3 Create a protected property for Color variable.

    //        Access modifier is "protected"

    //

    // Hint: protected vs private

    // A protected member is accessible within its class and by derived class instances.

    // Private members are accessible only within the body of the class or 

    // the struct in which they are declared/

​

    // [Code] 3.4 Create two properties: Base (double) and Height (double)

    //        Use auto-implementation

​

    // Default constructor

    public Triangle(string name, double b, double height, string color) 

    { 

        Name = name;

        Base = b; 

        Height = height; 

        Color = color;

    }

​

  public double CalculateArea()

  {

        return Base*Height / 2;

  }

​

public bool IsYellow()

{

    return Color.ToLower() == "yellow";

}

}

​

public class Program

{

    public static void Main()

    {

        Triangle t = new Triangle("Triangle", 8.5,4.2, "blue");

        Console.WriteLine(t.CalculateArea());

        Console.WriteLine(t.IsYellow());

    }

}