Inheritance

Program.cs

using System;

namespace Inheritance
{
    class Program
    {
        static void Main(string[] args)
        {
            Quadrat q = new Quadrat(123);

            Console.WriteLine(q.GetDiagonale());

            Console.ReadKey();
        }
    }
}

Quadrat.cs

using System;

namespace Inheritance
{
    class Quadrat : Rechteck
    {
        static double WURZEL2 = Math.Sqrt(2);

        public Quadrat(double laenge) : base(laenge, laenge)
        {

        }

        public override double GetDiagonale ()
        {
            return WURZEL2 * GetLaenge();
        }
    }
}

Rechteck.cs

using System;

namespace Inheritance
{
    class Rechteck
    {
        private double laenge;
        private double breite;

        public Rechteck(double laenge, double breite)
        {
            this.laenge = laenge;
            this.breite = breite;
        }

        public double GetLaenge()
        {
            return this.laenge;
        }
        public double GetBreite()
        {
            return this.breite;
        }

        public double GetUmfang()
        {
            return 2 * this.laenge + 2 * this.breite;
        }

        public virtual double GetDiagonale()
        {
            return Math.Sqrt(this.laenge * this.laenge + this.breite * this.breite);
        }

    }
}