Use Draft in Flange mode or Multi-surface draft to create a surface from a set of surface curves, at an angle relative to the original surface.
❒.
Pull surfaces from curves of an existing surface

in Flange mode.
Pull a single surface from tangent-continuous curves of existing surfaces

❒.
As each curve is added, it is highlighted in yellow, and a flange surface is built. A single flange surface is created no matter how many surface curves have been selected.

to test the continuity.
Use Object Edit > Align > Align 2008
to make the curves tangent.
to create a vector object).
Set the angle or height at a point along the surface
