Program:

The source code to demonstrate the trigonometry angles in radians is given below. The given program is compiled and executed successfully on Microsoft Visual Studio.

//C# program to demonstrate the trigonometry Angles 
//in radians using Math class

using System;

class Demo
{
    static void Main(string[] args)
    {
        double sinPi3;
        double cosPi3;
        double tanPi3;

        sinPi3 = Math.Sin(Math.PI / 3);
        cosPi3 = Math.Cos(Math.PI / 3);
        tanPi3 = Math.Tan(Math.PI / 3);


        Console.WriteLine("sin (pi/3)    = "+ sinPi3);
        Console.WriteLine("cos (pi/3)    = "+ cosPi3);
        Console.WriteLine("tan (pi/3)    = "+ tanPi3);
    }
}

Output:

sin (pi/3)    = 0.866025403784439
cos (pi/3)    = 0.5
tan (pi/3)    = 1.73205080756888
Press any key to continue . . .

Explanation:

Here, we created a Demo class that contains the Main() method. In the Main() method, we created three variables of double type.

sinPi3 = Math.Sin(Math.PI / 3);
cosPi3 = Math.Cos(Math.PI / 3);
tanPi3 = Math.Tan(Math.PI / 3);

In the above code we calculated the trigonometry angles based radians using predefined method of Math class, and then print the result on the console screen.