using System;

namespace _26._03._2020

{

//1

 class  ExtendedRandom:Random

    {

        public double NextDouble(double min, double max)

        {

            return NextDouble() * (max - min) + min;

        }

    }

    //2

     class Point2d

    {

        protected int x; // защищенное поле x

        protected int y; // защищенное поле x

        public Point2d(int x, int y)

        {

            this.x = x;

            this.y = y;

        }

         public Point2d() : this(1, 1)

        {

        }

         // метод возвращает значение координаты по ее названию

        public virtual int GetCoordinate(string name)

        {

            return name == "x" ? x : (name == "y" ? y : -1);

        }

        public new string ToString()

        {

            return "x={x}\ny={y}\n";

        }

         //3

         public virtual new bool Equals(object obj)

        {

            Point2d point = (Point2d)obj;

            if (point.x == this.x && point.y == this.y)

            {

                return true;

            }

            else

            {

                return false;

            }

        }

         //4

         //4.1

         abstract class Figure //абстрактный класс

    {

        public abstract double Square();//площадь

        public abstract double Perimeter();//периметр

    }

         //4.2

         class Circle : Figure //дочерний класс

    {

        private double radius;

        public Circle()

        {

            radius = 2;

        }

        public Circle(double radius)

        {

            this.radius = radius;

        }

        public override double Square()

        {

            return Math.PI * this.radius * this.radius;

        }

        public override double Perimeter()

        {

            return 2*Math.PI*this.radius;

        }

    }

     }

​

namespace _26._03._2020

{

    public class Program

    {

        public static void Main()

        { 

        //1

        ExtendedRandom er = new ExtendedRandom();

        Console.WriteLine(er.NextDouble(1, 5));

        Point2d point = new Point2d();

        Point2d point1 = new Point2d(1, 5);

        Point2d point2 = new Point2d(2, 2);

        Console.WriteLine(point.ToString());

        Console.WriteLine(point.Equals(point));

        if (point1.Equals(point1))

        {

            Console.WriteLine("Истина");

        }

        else

        {

            Console.WriteLine("Ложь");

        }

​

        if (point1.Equals(point2))

        {

            Console.WriteLine("Истина");

        }

        else

        {

            Console.WriteLine("Ложь");

        }

        Circle round = new Circle(14);

        Console.WriteLine("Площадь = {0:F}",round.Square());

        Console.WriteLine("Периметр = {0:F}",round.Perimeter());

    }

}

}

}

​