I am going to post here and hoping that someone jumps in and helps you. I have looked all over on this computer and can't find......... It was a video/you tube of edging like scallop where you sew a piece to the front of the binding area [good sides together] and then flip the top that you have sewn to the back of the quilt. I am so upset with myself that I can' find it. In your case the sides would look like they were prairie points.
I hope someone else can find the source or explain it more clearly.