Makes the seed face (A) symmetric to the target face (B) about a plane of symmetry (C) you select.

When you use this option, after you select the target face (B), you must also select a symmetry plane (C). The symmetry plane can be a planar face, reference plane, or principal plane on a coordinate system.

When the seed element is a planar face, it can change position and orientation to become symmetric to the target element.

When the seed element is a cylindrical face, the seed face can change position and size to become symmetric to the target element.

The symmetry relationship is persisted by default. You can turn the persist option off while in the command.

You can choose the symmetry command first. Then select the seed face(s), target face, and symmetry plane.

You can also create the seed select set first and then choose the symmetry command. Then select the target face and symmetry plane.