Explanation:
object snaps are modes that allow you to snap to specific points on objects. To snap to the centroid of a closed polyline, you should use the Geometric Center object snap mode. This mode will display an asterisk (*) marker when you move the cursor over the geometric center of a closed polyline or spline.
To use this mode, you can either:
* Click on the Object Snap icon in the Status bar and select Geometric Center from the menu.
* Type GCE at the command prompt or when prompted for a point and press Enter.
Now you can snap to the centroid of a closed polyline by using Geometric Center object snap.