By　means　of　a　combination　of　high-resolution　electron　microscopy　(HREM)　and　high-angle　annular　dark-field　scanning　transmission　electron　microscopy　(HAADF-STEM)　techniques,　we　have　directly　revealed　that　periodic　arrangements　in　different　manners　for　flattened　hexagons　constructed　with　atom　columnar　clusters　can　form　two　Al-Ni-Rh　crystalline　approximant　phases.　In　contrast　to　periodic　arrangements　of　flattened　hexagons,　configurations　and　distributions　of　various　defects　in　these　structurally-complicated　alloy　phases　have　been　examined　and　their　structural　characteristics　discussed.　HREM　observations　clearly　show　that　structural　defects　in　Al-Ni-Rh　crystalline　approximants　are　of　phason　type　and　they　are　correlated　with　incorrect　arrangements　of　atom　columnar　clusters.　The　distribution　of　high　density　planar　defects　can　destroy　the　long-range　periodicity　in　at　least　one　direction　in　the　pseudo　decagonal　symmetry　plane.　By　means　of　the　HAADF-STEM　imaging　technique,　the　existence　of　ill-formed　atom　columnar　clusters　in　the　core　area　of　a　linear　defect,　which　is　usually　not　visible　in　HREM　observations,　has　been　clearly　revealed.