How to draw a half-cirque in hf$$?

Hi
You can draw a circularity first ,rotate it around a aixs .notice the in-radius of cirque is the distance to the axis.
You can test
Caocao

Hi
p. s:The circularity is not cover! The solid is covered after rotated .
Regards !
CaoCao

Hi CaoCao,
I can't understand your method!
Pls practice it and upload here!

Thanka in advance!

Hi STD
I will add the example tomorrow,please wait for a day:)
CaoCao

HI
There is the example of cirque,two methods had been brought.