Creating Mirrored Elements  

This task shows you how to repeat existing Drafting geometry using a line, a construction line, an axis or a generated element. In this particular case, we will duplicate a circle.
Create a circle and a construction line.
  1. Select the circle to be duplicated by symmetry.

 
   
  1. Click the Mirror icon from the Geometry Modification toolbar.

 

 
  1. Select the axis you previously created.

The selected circle is duplicated and a symmetry constraint is created.

 
You can also use multi-selection. Drag the cursor and create a trap. Then select the symmetry axis.
If you take a generated element as axis, the symmetry constraint is not created.