using System;

public class Program
{
    public static void Main(string[] args)
    {
        Book b1 = new Book();
        b1.SetBook("Пушкин А.С.", "Капитанская дочка", "Вильямс", 123, 2012);
        Book.SetPrice(12);
        b1.Show();
        Console.WriteLine("\n Итоговая стоимость аренды: {0} р.", b1.PriceBook(3));

        Book b2 = new Book("Толстой Л.Н.", "Война и мир", "Наука и жизнь", 1234, 2013);
        b2.Show();

        Book b3 = new Book("Лермонтов М.Ю.", "Мцыри");
        b3.Show();


        Triangle t1 = new Triangle(3, 4, 5);
        t1.Show();
        Console.WriteLine("perimeter = {0}", t1.Perimeter());
        Console.WriteLine("area = {0}", t1.Area());
        Console.WriteLine("does this triangle exist? {0}", t1.Exists());

        Triangle t2 = new Triangle(3, 4, 7);
        t2.Show();
        Console.WriteLine("does this triangle exist? {0}", t2.Exists());

    }
}