Setting variable values in constructor, help

  abstract class Tree
    {
        public string name;
        private int age;
        private int length;

        protected Tree(string name, int age, int length)
        {
            this.age = age;
            this.length = length;
            this.name = name;
        }

        public int Age
        {
            get { return age; }
        }

        public int Length
        {
            get { return length; }
        }
    }

    class Oak : Tree
    {
        public Oak(string name, int age, int lengthInput)
            : base(name, age, lengthInput)
        {
        }
    }

In this particular case you are making sure your abstract class in setting your fields. You can also add the set in both properties and set the fields in the Oak constructor.