Select an editable poly object. > Modify panel > Polygon sub-object level > Edit Polygons rollout > Hinge From Edge Settings button
Select an editable poly object. > Polygon sub-object level > Quad menu > tools 2 quadrant > Hinge From Edge Settings button
Use these settings for hinging polygons in Interactive Manipulation mode.

Angle—Quantifies the rotation about the hinge. You can hinge selected polygons outward or inward, depending on whether the value is positive or negative.
Segments—Specifies the number of polygons into which each extruded side is subdivided. This setting also applies to manually hinged polygons.
Current Hinge—Click Pick Hinge, and then select an edge to be the hinge.
All subsequent hinge operations created via the dialog will use this hinge. To hinge multiple polygons, each from one of its own sides, you must reselect the hinge each time.
Web Designer - offers freelance web design services, redesign, graphic design, content
management, web development and e-commerce.
LTD