using System;

public class Program

{

    public static void Main()

    {

        double sumOfForce = 0;

        for(var angle = 0.0; angle < 180; angle+=0.001)

        {

            sumOfForce += Math.Sin(ToRadiant(angle)) / 180000;

        }

        double distance = 0.20;

        double arcLength = distance * Math.PI;

        var weight = 10;

        var g = 9.81;

        double energy = weight * g * sumOfForce * arcLength; // E = F * x

        Console.WriteLine("my method: {0} Joule", energy);

        Console.WriteLine("m.g.h = {0} Joule", (20 * g * 0.2));

        Console.WriteLine("m.g.h * Pi / 4 = {0} Joule", (20 * g * 0.2 * Math.PI / 4));

    }

    public static double ToRadiant(double degree) 

    {

        return degree * Math.PI / 180;  

    }

}