Modifiers matching polyhedron:

• convex,
• regular,
• useful,
• simple,
• hollow,
• symmetric,
• basic,
• complicated,

Simple categories matching symmetric:

• interface,
• processing,
• crystal,
• shape,
• object,
• material,
• surface,
• form,
• phase,
• structure,
• part,
• function,
• polygon,
• space,
• center,
• pattern,
• container,
• polyhedron,
• loop,
• cell,
• figure,
• window,
• site,
• pit,
• system,