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Isotoxal figure

Polytope or tiling with one type of edge

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Through Geometry, Polygon and Polyhedron

Isotoxal polygons

An isotoxal polygon is an even-sided i.e. equilateral polygon, but not all equilateral polygons are isotoxal. The duals of isotoxal polygons are isogonal polygons. Isotoxal 4n-gons are centrally symmetric, thus are also zonogons.

In general, a (non-regular) isotoxal 2n-gon has Dn,(∗nn) dihedral symmetry. For example, a (non-square) rhombus is an isotoxal "2×2-gon" (quadrilateral) with D2,(∗22) symmetry. All regular n-gons (also with odd n) are isotoxal, having double the minimum symmetry order: a regular n-gon has Dn,(∗nn) dihedral symmetry.

An isotoxal 2n-gon with outer internal angle α can be denoted by {nα}. The inner internal angle (β) may be less or greater than 180o, making convex or concave polygons respectively.

A star 2n-gon can also be isotoxal, denoted by {(n/q)α}, with q≤n−1 and with the greatest common divisor gcd(n,q)=1, where q is the turning number or density. Concave inner vertices can be defined for q<n/2. If D=gcd(n,q)≥2, then {(n/q)α}={(Dm/Dp)α} is "reduced" to a compound D{(m/p)α} of D rotated copies of {(m/p)α}.

Caution:

The vertices of {(n/q)α} are not always placed like those of {nα}, whereas the vertices of the regular {n/q} are placed like those of the regular {n}.

A set of "uniform" tilings, actually isogonal tilings using isotoxal polygons as less symmetric faces than regular ones, can be defined.

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