using System;

​

//1. Create an interface IShape

interface IShape

{

    //1.1 [Code] Declare one property Name (String)

    string Name { get; set; }

​

    //1.2 [Code] Declare one function CalculateArea()

    //Input: none

    //Output: double

    double CalculateArea();

}

​

//2. Create an interface IColor

interface IColor

{

    //2.1 [Code] Declare one property Color (string)

    string Color { get; set; }

​

    //2.2 [Code] Declare one function IsYellow()

    //Input: none

    //Output: bool

    bool IsYellow();

}

​

//3. Create a class inherit from IShape and IColor

public class Triangle : IShape, IColor //[Code] 3.1 Inherit from both Ishape and IColor

{

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

    //The length of name should be more than 0 (hint: use Length property of a string.)

    private string name;

    public string Name

    {

        get { return name; }

        set

        {

            if (value.Length > 0)

                name = value;

            else

                throw new ArgumentException("Name cannot be empty");

        }

    }

​

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

    //Use auto-implementation

    public string Color { get; set; }

​

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

    //Use auto-implementation

    public double Base { get; set; }

    public double Height { get; set; }

​

    //Declare base constructor

    public Triangle() { }

​

    //[Code] 3.4 Declare the second constructor with four parameters to set values for Name, Base, and Height, and Color

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

    {

        Name = name;

        Base = base_;

        Height = height;

        Color = color;

    }

​

    //[Code] 3.5 Implement CalculateArea function

    //Input: none

    //Output: double

    //Rule: Please use the formula to calculate the area for a triangle. (hint: use Base and Height).

    public double CalculateArea()

    {

        return 0.5 * Base * Height;

    }

​

    //[Code] 3.6 Implement IsYellow function

    //Input: none

    //Output: bool

    //Rule: if the color is yellow, return true; false, otherwise. (the color string should be case insensitive; hint: use ToLower())

    public bool IsYellow()

    {

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

    }

}

​

public class Program

{

    public static void Main()

    {

        //[Code] 1. Create a triangle object

        //input: "Triangle", 8.5, 4.2, "blue" (use one line)

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

​

        //[Question] What is the value of the area for the created triangle?

        //(Use Console.WriteLine and CalculateArea function to find the answer)

        //Ans:

        Console.WriteLine("Area: " + triangle.CalculateArea());

​

        //[Question] Is the triangle object's color yellow?

        //(Use Console.WriteLine and IsYellow function to find the answer)

        //Ans:

        Console.WriteLine("Is Yellow: " + triangle.IsYellow());

    }

}