为什么这个面积运行不了啊，救命！

Question

Answer 1

    class Program
    {
        static void Main()
        {
            double a, b, c; //三角形的三边长
                            //接收输入
            Console.WriteLine("请输入三角形的三边长");
            try
            {
                Console.Write("a : ");
                a = double.Parse(Console.ReadLine());
                Console.Write("b : ");
                b = double.Parse(Console.ReadLine());
                Console.Write("c : ");
                c = double.Parse(Console.ReadLine());
            }
            catch (Exception)
            {
                Console.WriteLine("边长必须是数值!");
                return;
            }
            //判断是否构造三角形
            if (a >= b + c || b > a + c || c > a + b)
            {
                Console.WriteLine("{0}、{1}、{2}不能构成三角形!", a, b, c);
                return;
            }
            double s = (a + b + c) / 2;
            double area;
            area = Math.Sqrt(s * (s - a) * (s - b) * (s - c));
            Console.WriteLine("{0}、{1}、{2}构成的三角形面积是{3}", a, b, c, area);
        }
    }