The options in Edit > Distribute > Special Distribute let you choose which point to distribute and along what to distribute the elements: a temporary line/arc drawn by you, or any existing line/edge.
Suppose you want to distribute potted plants in a circle around a hexagonal soil holder object:
Use Edit > Distribute > Special Distribute. Choose the “Draw a line or arc” option, then click OK to close the dialog box. Click to start drawing and choose the “Arc by centerpoint” pet palette option. You will create a temporary circle around the hexagonal object. As you complete the circle, the potted plants will be distributed around it.