Creo Interactive Surface Design (Style) > Curves > Editing Curves > To Extend a COS by Drop to Boundary
  
To Extend a COS by Drop to Boundary
1. In the Model Tree, right-click the Style feature that contains the curve to extend, and choose Edit Definition. The Style tab opens.
2. In the Style Tree, select one or more COS by drop, and then right-click and choose Edit Definition. The Drop Curve tab opens.
3. Click the Options tab.
4. Perform one or both of the following actions:
◦ Select the Start check box to extend the start point of the drop curve to the nearest surface boundary.
◦ Select the End check box to extend the end point of the drop curve to the nearest surface boundary.
 
• When you select more than one drop curve, the start points or end points for all the drop curves extend to the nearest surface boundary.
• When a curve is dropped onto a datum plane, you cannot extend the start or end point.
5. Click .