_Polygon :: (VectorStructureClass fv fc a) =>
  Prism' (GeometryStructure Polygon a fv fc) (Geometry Polygon a)
_Polygon = _PositionVector . _Geometry
_Polygon :: (VectorStructureClass fv fc a) =>
  Prism' (GeometryStructure Polygon a fv fc) (Geometry Polygon a)
_Polygon = _PositionVector . _Geometry
_Polygon = _PositionVector . _Geometry