https://forums.autodesk.com/t5/autocad-forum/draw-an-arc-tangent-to-2-lines/m-p/2879030#M349476 <P>The wheel hasn't been reinvented enough times in this thread, so here's my version.&nbsp; I am curious if this thing would work in R11.&nbsp; It's sure been a while since I used that version!</P><P>&nbsp;</P><P>LLARC.LSP defines the command LLARC.&nbsp; When you run LLARC, it prompts you to select a first LINE entity, then it prompts you to select a second different LINE entity.&nbsp; It then draws that arc with an included angle of less than or equal to 180 degrees tangent to the two lines, which ends at the point you picked when you selected the second LINE.&nbsp; There are two possibilities here: the first is that the two LINEs, if extended, intersect, and the second is that they do not intersect. For the case where the two lines intersect, there will be two solutions (see two-solution-1.gif) and LLARC chooses the solution where the arc is on the same side of the intersection point as the two pick points.&nbsp; For the case where they do not intersect, it could be that the two LINEs are colinear or nearly so (I arbitrarily chose a distance of less than 1e-10 drawing units apart as the cutoff) but if the two lines are an appeciable distance apart, you can draw an arc with an included angle of 180 degrees between them, but you don't know which way it goes, so LLARC prompts you to select the direction the arc goes.</P><P>&nbsp;</P><P>You might prefer to have the arc start at the point where you picked the first line instead of the second.</P> Wed, 12 Jan 2011 21:37:08 GMT Anonymous 2011-01-12T21:37:08Z