Extend extrusions

Hi, fellows!
I would like to extend the extrusions I made from floating lines.
I made the projections, but I dont know what’s the next step. Could you tell me how I can connect them? Or if there is a better way, please let me know.
(The yellow part is what I want to make. I am attaching the file for the refrence.)

0518_Model1(WORK3).gh (20.3 KB)