Topic: Arc by two points tangent to a line?

[surveyor_randy]

Good afternoon all,
I'm trying to clean up some linework that the crews brought in.  Typically, they shoot the PC of an arc, a point on the arc and then the end of the arc.  But 9 out of 10 times, they don't get the PC quite right and the linework looks crappy and I go in and fix it by hand.  I was trying to do this today and noticed that when I use the standard 3 point arc command, it won't let me snap tangent to the tangent line coming into the arc.  Is there any lisp of C3D routine that will let me draw an arc through two points and tangent to a line?  Thanks in advance for any suggestions.  Right now, I'm just snapping nearest on the line and kinda "eyeballing" it in there.  I'd like to have proper geometry though!  You know how surveyors get about geometry! 

[danallen]

Try redrawing the line, then start arc command immediately after, hitting enter for 1st point, it should use the just created line for a tangent.

Dan

[surveyor_randy]

danallen, thanks for the reply.  This was actually an Autocad question and I posted this in the Carlson forum accidently.  Mods, could you please move this to "Land Lubber"?  Thanks!

[Dent Cermak]

Same solution for either Carlson or AutoCad: Draw Arc by Start,End,Direction will work for what you want.