As an alternative, I'm a fan of drawing a square and then deleting one of its points. (In FW, this would mean drawing a rectangle while holding the Shift key, then selecting a point with the Subselect tool, opting to ungroup the rectangle, and deleting the point.)
It's odd that there'd be no sides in the Properties inspector when working with the standard Polygon shape.
Its the first day I use FW so I could have done somthing wrong I am not sure if I have ungrouped anything. I just draw a smart polygon from the toolbox without any further editing. If you ungroup anything will it then take effect on shapes I draw in the future? I dont see the tooltip either like you do.
I am not exactly sure what I did. I removed textture and then I got the little yellow rect like you have. I could then drag it up and down for more or less sides and that worked. Thanks a lot.