How can I draw line tangent two curves on a surface?

Rhino Rhino for Windows
1

Hi,
V4 V5

I have a circle and a curve both of which are projections on the surface. I need a line also following the surface tangent to these two.

How is that done ?

Also how can I use curve drawing tools on a surface ?

Steve

2

Can you share the example file?

3

Like to do what?
There’s the OnSrf object snap and the InterpCrvOnSrf command. Check the Help.