Creo Interactive Surface Design (Style) > Curves > Editing Curves > About Close Points
  
About Close Points
When you create a closed curve, the point at which the curve starts and ends is called the close point. It consists of two coincident points:
• Start point—Defines the start of the curve and the leader tangent.
• End point—Defines the end of the curve and the follower tangent.
 
* The close point of a circle created in a Style feature is the point where the radius meets the circumference.
A close point is represented by in the graphics window. The dot represents the start point, and the x represents the end point that is snapped to the start point. You can use the shortcut menu to toggle selection between the start point and the end point. You can also redefine the end point by selecting a new end point on the curve. You must unlink the close point before you can split the closed curve.