private static void Heron()
{
// Formula: : S=sqrt{p(p-a)(p-b)(p-c)}
// p = Perimeter / 2
Console.Write("Enter side 'a': ");
double a = double.Parse(Console.ReadLine());
Console.Write("Enter side 'b': ");
double b = double.Parse(Console.ReadLine());
Console.Write("Enter side 'c': ");
double c = double.Parse(Console.ReadLine());
double Perimeter = a + b + c;
double p = Perimeter / 2;
double S = Math.Sqrt(p * (p - a) * (p - b) * (p - c));
Console.WriteLine("S = {0}", S);
}