View
DisplayBoundary + Hidden Lines
The Boundary View and Hidden Lines command displays the objects in the model such that the visible boundaries appear in the view as continuous lines. Surface boundaries that are hidden from view by other surfaces in the model (hidden lines) are also shown. The line type for the hidden lines should be changed to "dashed" by selecting the Dashed hidden line mode check box in the Graphics category in the System Options tab of Options/Properties dialog box.