Line Tangent to Curve

I was surprised not to see this question (except related to scripting).

Is there a way to draw a line from a specific point to a tangent on a curve.

E.g., I pick a point, then select a arc and get a line from the specified point to a point on the arc that creates a tangent?

Yep, the Tan Osnap should find that point.
http://screencast.com/t/uR8dXYZEQ

-Pascal

Thanks, I figured it would be simple.