using System;

// 1. Create an interface IShape

public 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

public 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. If length is zero,

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

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

    private string _Name;

    public string Name{

        get{

            return _Name;}

        set{

            if (value.Length ==0){

                Console.WriteLine("Name must be longer than 0 characters.");

            }

            else _Name = value;

        }

    }

    // [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/

    protected string _color;

    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;}

    // Default 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 N, double B, double H, string C) {

    Name = N;

    Base = B;

    Height = H;

    Color = C;}

    // [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 Base*Height*.5;

    }

    // [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

    public bool IsYellow(){

        if(Color.ToUpper() == "YELLOW"){

        return true;}

        else return false;

    }

}

​

public class Program

{

    public static void Main()

    {

        // [Code] 1. Create a triangle object

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

        Triangle one = 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)

        Console.WriteLine(one.CalculateArea());

        // Ans: 17.85

​

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

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

        Console.WriteLine(one.IsYellow());

        // Ans: False

    }

}