Circular shapes represent completeness while overhead planes offer protection and define space. Ceiling planes can reflect structural systems and provide a second coating. Architectural openings can manipulate space visually and spatially. There are five primary solids with cubes having six equal sides and being stable while spheres have no focal point. Cluster organization uses proximity to connect places and radial organization combines linear and centralized structures around a core area. Linked spaces can form large regions or defined volumes.