2-Point Arc via two methods - Different Results

Two different scenarios in creating a 2 point arc, guide points and line segments:

  1. Two guide points, each spaced 5"
  2. Two lines, each 5" in length

Condition 1, the vertex points are not tangent.
Condition 2, the vertex points are tangent, but the lines disappear after the arc is created.


  1. I use guide points frequently, why do these not produce a tangent vertex? Is it possible to use guide points?
  2. Why are the original line segments deleted after the arc is established?

As the video shows the behavior of the arc tool is significantly different in the two scenarios.

As always, appreciate any guidance. Thanks

Starting condition (guide points barely visible):

After using arc tool:

Video: (shown was a snap point using guide points)

Guide points don’t create lines that can help the Arc Tool to create a tangent arc since there is no line to which it can get an inference.

Guide lines cannot act better than guide points.

You need real lines or edges to allow the Arc Tool to infer a tangent. However, the Arc Tool is programmed to delete the two tangents since it is often used to get rounded corner. This automatic deleting saves you a step.

In your case, if you want to keep the two edges, you have two choices:

1 - Redraw the two edges after the arc is created.

2 - Create a group with the two edges before creating the arc. Then they won’t be erased once the arc is done. If needed, you can explode the group afterward.


To keep the edges, click once at the magenta point then move back until magenta again and single click to finish.