Isosceles Triangle - Mirror Upper and Lower Halves

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

class IsoscelesTriangleFive
{
    static void Main()
    {
        Console.OutputEncoding = Encoding.Unicode;

        string copyright = '\u00A9'.ToString();
        int b = 4;

        // The halfTriangle list will be storing the upper half of our isosceles triangle
        List<string> halfTriangle = new List<string>();

        halfTriangle.Add(copyright);

        // calculates all strings necessary for one cathetus of the triangle
        // stores them in the halfTriangle list
        do
        {
            string space = new String(' ', b);
            string print = copyright + space + copyright;
            halfTriangle.Add(print);
            b = b + 4;
        } while (b != 24);

        // printing the upper half of the triangle
        for (int i = 0; i < halfTriangle.Count; i++)
        {
            Console.WriteLine(halfTriangle[i]);
        }

        // printing the lower half of the triangle
        for (int i = halfTriangle.Count - 2; i >= 0; i--)
        {
            Console.WriteLine(halfTriangle[i]);
        }
    }
}