static void Main(string[] args)
{
//Bai 2
//Book book1 = new Book("B1234", "Mindset", 7000, 700);
//book1.giaSachFinal();
//Bai 5
Circle ht1 = new Circle(-1);
Circle ht2 = new Circle(2);
Console.WriteLine("Dien tich hinh tron1: " + ht1.dientich());
Console.WriteLine("Chu vi hinh tron1: " + ht1.chuvi());
Console.WriteLine("Dien tich hinh tron2: " + ht2.dientich());
Console.WriteLine("Chu vi hinh tron2: " + ht2.chuvi());
//Bai7
//Console.Write("Nhap vao trai banh n=");
//int n = int.Parse(Console.ReadLine());
//Ball[] ht = new Ball[n];
//for(int i = 0; i < n; i++)
//{
// ht[i] = new Ball();
//}
//Console.Write("Trai banh dau tien ");
//ht[0].inPut();
//for(int i = 0; i <n; i++)
//{
// ht[i].outPut();
//}
//ht[0].Throw();
//ht[1].Throw();
//ht[0].Pop();
//ht[0].Throw();
//for(int i = 0; i < n; i++)
//{
// Console.Write("So lan nem banh {0} la {1}", i + 1, ht[i].timeofthrow);
//}
Console.ReadKey();
}
