Radial scale?

I have an umbrella and I had 20 segments, now I have to make another pattern. So I just wanted to delete the pieces, as the pattern makes only sense with 18 segments, not 20 anymore.
Is there a way to somehow scale them around one rotation point? And close them to one umbrella again? Having 18 segments.

How would you do this?

Thank you

You can create 2 surfaces with Revolve command, and then use FlowAlongSrf
2023-04-20 13_38_33-Window