public int pi, yaricap;
        public Daire(int a, int b)
        {
            this.pi = a;
            this.yaricap = b;
        }
        public int alanhesapla()
        {
            return pi * (yaricap * yaricap);
        }
        public int cevrehesapla()
        {
            return 2 * pi * yaricap;
        }