Editing Pattern (section)

=== Symmetry ===
[[File:First Snowfall (38115232341).jpg|thumb|upright|[[Snowflake]] [[dihedral symmetry|sixfold symmetry]]]]
Symmetry is widespread in living things. Animals that move usually have bilateral or [[Reflection symmetry|mirror symmetry]] as this favours movement.<ref name=":0" />{{Rp|pages=48–49}} Plants often have radial or [[rotational symmetry]], as do many flowers, as well as animals which are largely static as adults, such as [[sea anemone]]s. Fivefold symmetry is found in the [[echinoderms]], including [[starfish]], [[sea urchin]]s, and [[sea lilies]].<ref name=":0" />{{Rp|pages=64–65}}

Among non-living things, [[snowflake]]s have striking [[dihedral symmetry|sixfold symmetry]]: each flake is unique, its structure recording the varying conditions during its crystallisation similarly on each of its six arms.<ref name=":0" />{{Rp|page=52}} [[Crystal]]s have a highly specific set of possible [[crystal habit|crystal symmetries]]; they can be cubic or [[octahedral]], but cannot have fivefold symmetry (unlike [[quasicrystals]]).<ref name=":0" />{{Rp|pages=82–84}}