To Mirror All the Geometry in a Part
1. Select the part name at the top of the Model Tree.
2. Click > 
Mirror. The Mirror tab opens.
Mirror. The Mirror tab opens.3. Select a planar reference to mirror across. You can select a datum plane, intent datum plane, or planar surface.
 | You can redefine the Mirror plane by clicking a planar reference to mirror across. You can select a datum plane, intent datum plane, or planar surface. |
4. To define the bodies to which the feature is added, click the Body Options tab and select an option:
◦ To add the mirrored solid geometry from each body to the same body that it was copied from, select Original bodies.
◦ To add the mirrored solid geometry from each body to a new body, select New bodies.
5. Click 
OK.
OK.