int   a, b, c;
           int   s,p;
            Console.WriteLine("请输入三角形的三条边");
            a = Convert.ToInt32(Console.ReadLine());
            b = Convert.ToInt32(Console.ReadLine());
            c = Convert.ToInt32(Console.ReadLine());
           s = Convert.ToInt32(Console.ReadLine());
          p = Convert.ToInt32(Console.ReadLine());
            s= (a + b + c) / 2;
            s = (p - a) * (p - b) * (p - c) * p;
           Console.WriteLine("Math.Sprt(s)={0}", Math.Sqrt(s));
          
           Console.WriteLine("三角形的面积是s={0}",s);
           Console.ReadLine();