I was hoping to be able to colour in a pie-shaped wedge by restricting theta, for example:

polarplot([cos(t), sin(t), t = (1/16)*Pi .. 3*Pi*(1/16)], color = "NavyBlue", thickness = 3, filled = [color = "Blue", transparency = .5])

But it doesn't do what I had hoped.  Am I doing something wrong?

Thanks for the link.  I figured out a way to do what I wanted by transfering the Maple graph into MS Word and changing the graph's white background to transparent, then superimposing it on the map.  

Thanks for the link.  I figured out a way to do what I wanted by transfering the Maple graph into MS Word and changing the graph's white background to transparent, then superimposing it on the map.