If you want to sew your own wing seam in our 45×108 semicircle how you want to do it depends on what type of dowel you will be using and what length; one with knobs (which won’t fit in the pocket) or without.
If you want to be able to use a 36″ dowel (see the 411 on Wings for more info) and/or a 48″ but neither will have a knob (larger ball to grip on one end), then I suggest using the option (dotted line is the seam) below. It also works if you only want to use a 48″ knobbed dowel.
However if you want to be able to use either 36″ and 48″ dowel with a knob, try using the option below:
Sew the seam (dotted line) to the ~36″ mark, then leave a slight opening (where a 36″ dowel with a knob could go and then do a second seam that would accommodate a 48″ dowel with a knob.
Hope this helps!