c# - ユーザー入力に基づいて計算を行う方法

Question

これが私のコードブロックですが、胴回りと体積を計算する方法がわかりません。たとえば、最初の 4 つのパラメータに 1,1,1,1 を入力すると、体積と胴回りに 0, 0 が返されます。

       if (packages == 1)
        {

            int width = 0, length = 0, height = 0, weight = 0;
            int volume = 0, girth = 0;
            int[] packageInfo = new int[6] { width, length, height, weight ,volume, girth };
            packageInfo[4] = height * width * length;
            packageInfo[5] = (2 * length + 2 * width);
            double packageSum = 0;


            for (int k = 0; k < 4; k++)
            {
                string line = Console.ReadLine();
                if (!int.TryParse(line, out packageInfo[k]))
                {
                    Console.WriteLine("Couldn't parse {0} - please enter integers", line);
                    k--;
                }
            }

            if(packageInfo[3] > 25)
            {
                packageSum = 0;
                Console.WriteLine("Package couldn't be shipped because of its size.");
            }
            if (volume > 4800)
            {
                packageSum = packageSum + 5.95;
            }

            if (volume > 9600)
            {
                packageSum = 0;
                Console.WriteLine("Package couldn't be shipped because of its size.");
            }

            foreach (var item in packageInfo)
                Console.WriteLine(item.ToString());

        }