用C#编写程序,实现:输入三个非负数a、b、c,如果能构成三角形就求出它的面积

using System;
class Triage
{
   public static void Main()
   {
     int a=0,b=0,c=0;
     double p=0,area=0;
     Console.WriteLine("a=");
     a=int.Parse(Console.ReadLine());
     Console.WriteLine("b=");
     a=int.Parse(Console.ReadLine());
     Console.WriteLine("c=");
     a=int.Parse(Console.ReadLine());
     if(a+b>c&&a+c>b&&b+c>a)
      {
         p=(a+b+c)/2d;
         area=Math.sqrt(p*(p-a)*(p-b)*(p-c));
         Console.WriteLine("area="+area);
      }
     else
     {
        Console.WriteLine("Error in input data!");
     }
     Console.ReadKey();
  }
}
      
         

 

class Triangle
    {
        protected double a;
        protected double b;
        protected double c;
        public Triangle(double a ,double b,double c)
        {
            this.a = a;
            this.b = b;
            this.c = c;
        }
        public bool IsTriangle()
        {
            if (a + b <= c || a + c <= b || c + b <= a)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
        public double GetArea()
        {
            if (!IsTriangle()) return -1.0;

            double temp = (a + b + c) * 1.0 / 2;

            temp = System.Math.Sqrt(temp * (temp - a) * (temp - b) * (temp - c));

            return temp;
        }
}