How to draw a line when starting point, angle length are given using C#

Using some code from msdn
http://msdn.microsoft.com/es-es/library/f956fzw1(v=vs.110).aspx[^]

Starting point needs x y coords. Lets say you have them. And you have the angle in radians, and length:

int x = 500;
int y = 600;
decimal angle = 1.5;
int length = 400;


public void DrawLinePoint(PaintEventArgs e)
{

    //cosA = x/h
    //AND sinX = y/h


    // Create pen.
    Pen blackPen = new Pen(Color.Black, 3);

    // Create points that define line.
    Point point1 = new Point(x, y);
    Point point2 = new Point(x + Math.Cos(angle)*length, y + Math.Sin(angle)*length);

    // Draw line to screen.
    e.Graphics.DrawLine(blackPen, point1, point2);

    //PLEASE NOTE THAT YOU MAY NEED ADDITIONAL ROUNDING OPERATIONS, SINCE X Y COORDS ARE MEANT TO BE INTs
}