-
If a point is selected (mono-tangent mode): a vector tangent to the
curve is displayed at the selected point.
-
If a second curve is selected (or a point in bi-tangent mode), you
need to select a support plane. The line will be tangent to both
curves.
When several solutions are possible, you can choose one
(here displayed in green) directly in the geometry, or using Next
Solution
: