Generate 2D polygon that always touch 2 specific points

I wanted to create a 3d tree structure by lofting different polygon sections, the problem is how to create various polygons section that always touches the 2 profile curves? At the moment my polygons are generated by various radius based on the distance between the 2 curves at different points, the result is ok but the polygons do not touch the profile curve so the resulting loft does not exactly follow the shape of the curve. Could anybody help? Thanks!

I think you can do it by differentiating polygons with odd edges and even edges.image
Hope it can help you. (16.9 KB)

thank you so much!