Circumarc

Click the New Circumarc tool on the String Editor toolbar (Strings | Edit | New Arc | Circumarc) to digitise an arc from an arc start point, an arc mid-point, and an arc end point.

When three points have been digitised, you can adjust the size and position of the arc in the Circumarc Properties form:

First, Second and Third Points

If necessary, adjust the coordinates of the arc's points to alter its size and position.

Points

Specify the number of points along the arc.

Preview

Click the Preview button to see a preview of the new arc. If you are happy with the result, click OK. Otherwise adjust the parameters you have entered and preview again.