To Modify the Diameter of an Arc or Circle
1. Select the circle or arc and right-click to display the shortcut menu.
2. Click Edit Diameter Value from the shortcut menu.
3. Type a new diameter for the draft entity. The entity reappears at its modified value.
4. To update any associated draft dimensions, choose Edit > Regenerate > Draft.
When you modify the diameter of an arc or circle, the system does not update unassociated draft dimensions to reflect changes in the entity size.