using System;

​

public abstract class Shape {

    public int numSides{

        get;

        protected set;

        }

    public int width;   

    public int height;

    public abstract int getArea ();

    public abstract double getPerimeter ();

    protected Shape() {

        this.numSides = 0;

    }

    protected Shape(int sides) {

        this.numSides = sides;

    }

}

​

public class Rectangle: Shape {

    public Rectangle(int w, int h) {

        this.numSides = 4;  

        this.width = w;

        this.height = h;

    }

    public override int getArea (){

        return (width * height);

    }   

    public override double getPerimeter (){

        return (width * 2 + height * 2);

    }

}

​

public class IsoscelesTriangle: Shape {

    public IsoscelesTriangle(int w, int h) {

        this.numSides = 3;  

        this.width = w;

        this.height = h;

    }

    public override int getArea (){

        return ((width * height) / 2);

    }   

    public override double getPerimeter (){

        return ( width + ( Math.Sqrt(Math.Pow(width / 2, 2) + Math.Pow(height, 2) ) * 2 ) );

    }

}

public class Program

{

    public static void Main()

    {

        Shape rectangle = new Rectangle(5, 8);

        Console.WriteLine("Rectangle area: {0}", rectangle.getArea());

        Console.WriteLine("Rectangle perimeter: {0}", rectangle.getPerimeter());

        Shape isocelestriangle = new IsoscelesTriangle(5, 8);

        Console.WriteLine("Triangle area: {0}", isocelestriangle.getArea());

        Console.WriteLine("Triangle perimeter {0}", isocelestriangle.getPerimeter());

    }

}

​

​