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

namespace ch7_4
{
        public abstract class Shape
        {
            public virtual double area()
            {
                return 0;
            }
            public virtual double volume()
            {
                return 0;
            }

            public abstract string Name
            {
                get;
            }
        }
}
