Howdy,
Our good major has it wrong since you are talking about drawing actual 2d polygons and he is talking about the polygons used to render 3d surfaces in openGL. They are not related in the least.
All that you need to do is create a closed path and fill it to get that in Quartz. The easiest way at the appkit level is just to make a closed bezier path and then fill it. You can use solid colors, gradients, tiled images almost anything like that.
If you are just doing 2d stuff you really should not get into OpenGL as there are lots of complications that will not help in the 2D case.