Some can help to give advice of Arc Drawing in grasshopper(with a tangent line and the center of the circle is on the Y-axis)? )

Hey Everyone,
I am a new beginner and now trying to draw a arc in grasshoper,as in picture.
I have already the figure in blue line in Rhino,ang want to in grasshopper draw a arc ,which tangent to line 1,and point of tangency is A,the center of the arc is on the on the Y-axis. then delete the two red marked line
I try to figure it like this and to delete line I try to use GHpython but didn’t work.

Can someone give me some advice? (4.3 KB)
Thank you so much!

You need to either Internalise your Curves, or upload the .3dm file you referenced your Curves from. (19.5 KB)

hello Mahdiyar,
Thank you very much. This is what I want.
And can you tell me ,why do we need a ‘‘Domain’’ here?
Thank you !