Creo Direct > Designing in the Creo Direct Environment > Working in Part Mode > Working with 2D Geometry > Editing 2D Geometry > To Mirror Geometry
  
To Mirror Geometry
1. Make sure the sketch contains a centerline.
2. Select an entity or multiple entities to mirror.
3. Click Sketch > Mirror.
4. Click a centerline. The system mirrors all selected geometry about the selected centerline.