// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002323/double-atan

​

// @nuget: Z.ExtensionMethods

​

using System;

public class Program

{

    public static void Main()

    {

​

        double angle;

        double radians;

        double result;

​

        // Calculate the tangent of 30 degrees.

        angle = 30;

        radians = angle * (Math.PI / 180);

        // C# Extension Method: Double - Tan

        result = radians.Tan();

        Console.WriteLine("The tangent of 30 degrees is {0}.", result);

​

        // Calculate the arctangent of the previous tangent.

        // C# Extension Method: Double - Atan

        radians = result.Atan();

        angle = radians * (180 / Math.PI);

        Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle);

    }

}