Unable to join Planar Curve and Arc-like curve

I’d like to ask you a question. Two pieces of data, one is flat and one is three-dimensional. How can I make that flat piece of data three-dimensional

Now they’re not connected because they’re not in the same dimension

Can anyone solve this problem? help help

Right click C and flatten this input.

Thanks, I just did what you said but it still didn’t work out.

It is difficult to say without the actual file.

If possible post a Grasshopper file with the inputs internalized (Right click / internalize)

Problem solved. Thank you very much!!

Without a clear description of the problem (preferably a GH file) and solution, this thread is useless.