Mirror in a 3D Sketch
In mirroring, symmetry constraints are added between the original elements and those that are created as a result of mirroring.
- Select in the 3D sketch the lines and faces, which you want to mirror.
 - Select the context-sensitive function 
 Mirror. - Select the symmetry plane based on which the mirroring will be conducted. Select a planar face from the model.
If the editing mode of the assembly is active, you can select the face from other parts.
 - Select Confirm.
 
