using System;

​

public class Program

{

    public static void Main()

    {

        double semiPerimeter, sideA, sideB, sideC, diffSideA, diffSideB, diffSideC;

        Console.WriteLine("Enter the sides of A, B, C of triangle:");

        sideA = Convert.ToInt32(Console.ReadLine());

        sideB = Convert.ToInt32(Console.ReadLine());

        sideC = Convert.ToInt32(Console.ReadLine());

        semiPerimeter = (sideA + sideB + sideC) / 2;

        double area = Math.Sqrt(semiPerimeter * (semiPerimeter - sideA) * (semiPerimeter - sideB) * (semiPerimeter - sideC));

        diffSideA = semiPerimeter - sideA;

        diffSideB = semiPerimeter - sideB;

        diffSideC = semiPerimeter - sideC;

        double perimeter = diffSideA + diffSideB + diffSideC;

        Console.WriteLine("Area and perimeter of triangle are :{0} {1} respectively \n", area, perimeter);

    }

}