Here is a scale image of three different relative slopes of the pavilino walls.
All three "sizes" have the same dimensions on the ground. The image is based upon the calculations for using 12 spokes with varying lengths. All three are equally stable, but I find that the 7ft long spokes provide more usable room, yet retaining the nice sloped shape.
While the lines shown are perfectly straight, because canvas sags, I find that the 6 ft foot spokes result in a fair amount of unusable space, and the 7ft spokes fix this.