Our four foot diameter designer cage is pentagon shaped and the rear corner is at 90 degrees. This allows it to snugly fit into any walled corner, or to stand alone as shown. The actual diameter of this unit is 3.5 ft. by 4.5 ft. The door panel may be placed on any of the sides to fit your needs. Although the grate, trays and casters kit (normally added for indoor use) may be used outdoors, we recommend placing directly on an existing slab or 25 1 ft. x 1 ft. inexpensive concrete pavers; or if pouring a rectangular slab, the diameter needs to be 5 ft. This way you can simply hose it off every day or two with no need to clean the bottom.