Drawing Arrow between two points in ASP.NET

I am dynamically generating an image in ASP.NET. How can I dra开发者_运维百科w an arrow instead of the line in the below code snippet. I couldn't find any API for this.

Bitmap image = new Bitmap(640, 480);
Graphics graphics = Graphics.FromImage(image);
.
.
graphics.DrawLine(new Pen(Color.Red), lPoint, rPoint);

Bitmap image = new Bitmap(640, 480);
Graphics graphics = Graphics.FromImage(image);
Pen p = new Pen(Color.Red, 10);
p.EndCap = LineCap.ArrowAnchor;
graphics.DrawLine(p, lPoint, rPoint);

See LineCap Enumeration MSDN