Use this procedure to merge geometry into a 2D section. When you merge linework into a section, you assign additional linework to a display component of a section. Use this feature to add detail, or to add linework that you did not model.
You can also click (Match existing linework) and select linework in the section whose display component you want to match.
The linework is merged into the 2D section. When you select the section, the linework is selected with it.