C# Returns Angle whose Tangent is the Given Number

using System;

class Sample
{
    public static void Main()
    {
        double x = 1.0;
        double y = 2.0;
        double angle;
        double radians;
        double result;

        // Calculate the tangent of 30 degrees.
        angle = 30;
        radians = angle * (Math.PI / 180);
        result = Math.Tan(radians);
        Console.WriteLine("The tangent of 30 degrees is {0}.", result);

        // Calculate the arctangent of the previous tangent.
        radians = Math.Atan(result);
        angle = radians * (180 / Math.PI);
        Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle);

        // Calculate the arctangent of an angle.
        String line1 = "{0}The arctangent of the angle formed by the x-axis and ";
        String line2 = "a vector to point ({0},{1}) is {2}, ";
        String line3 = "which is equivalent to {0} degrees.";

        radians = Math.Atan2(y, x);
        angle = radians * (180 / Math.PI);

        Console.WriteLine(line1, Environment.NewLine);
        Console.WriteLine(line2, x, y, radians);
        Console.WriteLine(line3, angle);

        Console.Read();
    }
}

 

Output