How to fill an irregular closed area of the form?

Is it possible to fill an irregular closed area of a form??
I closed the area with lines like:

line(0,0)-(50,50)
line (50,50)-(20,20)
line(20,20)-(0,0)
(triangle)

thanks!

This may not be exactly what you're after, but it may give you some idea of what you can do with polygons.

http://www.vb-helper.com/howto_gradient_polygon.html

Hope this helps