two-fold rotational symmetry

Rotation by 180° about a center leaving the pattern invariant

Neighborhood — ranked by edge-count

paper

concept

Rotational Symmetry
related_to
One of four key isometries; rotation about a point through a given angle, with n-fold variants based on 360°/n invariance.
p112 Frieze Pattern
associated_with
Second frieze type; has two-fold rotational symmetry but no reflections or glide-reflections.
pmg2 Frieze Pattern
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Sixth frieze type; has two-fold rotational symmetry, vertical reflection symmetry, and glide-reflection symmetry.
pmm2 Frieze Pattern
associated_with
Fifth frieze type; has reflection symmetry in two directions and two-fold rotational symmetry.

cosine ≥ 0.65 · no typed edge

Entities in the same semantic neighborhood but without a typed relation to this one — candidates for new edges or unrecognized duplicates.

rotation symmetryconcept0.835
Rotation about a point by an angle 360°/n leaving the pattern invariant
Reflection Symmetryconcept0.746
One of four key isometries; reflection across a line (mirror line or axis of reflection).
Translation Symmetryconcept0.745
Movement in a given direction through a given distance; all frieze patterns possess this symmetry by definition.
Glide-Reflection Symmetryconcept0.727
One of four key isometries; combination of reflection and translation parallel to the mirror line.
LOCAL SYMMETRYconcept0.725
One of Alexander's fifteen properties; appears in birthday table, handshake, and namaste examples
Local-Symmetry Transformationconcept0.714
A transformation that strengthens a center by giving it an internal axis of symmetry, local to the center.
Counterchange Symmetryconcept0.713
Property where background and foreground tiles have identical shapes; observed in pmg2 patterns at the Alhambra.
Left Right Asymmetryconcept0.713
Bioelectrical circuits that set left-right organ placement; a morphogenetic decision akin to brain lateralization.