using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication2
{
    public class Figura
    {
        protected double a;
        protected double b;

        public Figura(double a, double b)
        {
            this.a = a;
            this.b = b;


        }
        public virtual double PoleFigury()
        {
            System.Console.WriteLine("Niezdefiniowana figura");
            return 0;


        }
    }
    public class Prostokąt : Figura
    {
        public Prostokąt(double a, double b) : base (a,b)
        { }
        public override double PoleFigury()
        {
            double pole = a * b;
            System.Console.WriteLine("Obliczamy pole prostokąta");
            return pole;

        }
    }
    public class Trojkat : Figura
    {

        public Trojkat(double a, double b) : base(a,b)
        { }
        public override double PoleFigury()
        {
            double pole = (a * b) / 2;
            System.Console.WriteLine("Obliczamy pole trójkąta");
            return pole;
        }

    }
    class glowna

    {
        static void Main(string[] args)
        {
            Figura f = new Figura(5,6);
            Prostokąt p = new Prostokąt(7, 8);
            Trojkat t = new Trojkat(9, 10);

            System.Console.WriteLine("Pole wynosi {0}", f.PoleFigury());
            System.Console.WriteLine("Pole wynosi {0}", p.PoleFigury());
            System.Console.WriteLine("Pole wynosi {0}", t.PoleFigury());


        }
    }
}