To Mirror an Entity
Using the Mirror command you can create copies of draft entities, unattached symbols, and unattached notes by mirroring them about a draft line straight entity.
1. Click Sketch > Mirror.
2. Select detail items to mirror; then click the middle mouse button. You are prompted to select the line to mirror about. You can select the following entities for mirroring:
Drawn line
Construction line
Draft axes
Draft datum planes
Snap lines
Model datum planes that are perpendicular to the drawing sheet
Model datum axes
Model Edges
When you select the line an entity, the mirror copy is created opposite the original, equidistant from the center line.
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For mirroring you can select any model edge that appears straight. This includes circular or non-straight edges in a model that have their line of sight perfectly straight in the drawing view.
The following are not a part of straight entities, and hence are not supported as mirroring planes:
Straight-line entities within dimensions
Straight-line entities within symbols
Leader lines on symbols, dimensions, and notes
GTOL control frames
Half view lines from Half Views
Entities in formats