In
geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ...
, the truncated square tiling is a
semiregular tiling by regular polygons
Euclidean plane tilings by convex regular polygons have been widely used since antiquity. The first systematic mathematical treatment was that of Kepler in his ''Harmonices Mundi'' (Latin: ''The Harmony of the World'', 1619).
Notation of Eucl ...
of the
Euclidean plane with one
square
In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
and two
octagons on each
vertex. This is the only edge-to-edge tiling by
regular convex polygon
In geometry, a convex polygon is a polygon that is the boundary of a convex set. This means that the line segment between two points of the polygon is contained in the union of the interior and the boundary of the polygon. In particular, it is a ...
s which contains an octagon. It has
Schläfli symbol of ''t''.
Conway calls it a truncated quadrille, constructed as a
truncation operation applied to a
square tiling
In geometry, the square tiling, square tessellation or square grid is a regular tiling of the Euclidean plane. It has Schläfli symbol of meaning it has 4 squares around every vertex.
Conway called it a quadrille.
The internal angle of th ...
(quadrille).
Other names used for this pattern include Mediterranean tiling and octagonal tiling, which is often represented by smaller squares, and nonregular octagons which alternate long and short edges.
There are 3
regular and 8
semiregular tilings in the plane.
Uniform colorings
There are two distinct
uniform coloring
In geometry, a uniform coloring is a property of a uniform figure (uniform tiling or uniform polyhedron) that is colored to be vertex-transitive. Different symmetries can be expressed on the same geometric figure with the faces following differ ...
s of a truncated square tiling. (Naming the colors by indices around a vertex (4.8.8): 122, 123.)
Circle packing
The truncated square tiling can be used as a
circle packing
In geometry, circle packing is the study of the arrangement of circles (of equal or varying sizes) on a given surface such that no overlapping occurs and so that no circle can be enlarged without creating an overlap. The associated '' packing de ...
, placing equal diameter circles at the center of every point. Every circle is in contact with 3 other circles in the packing (
kissing number
In geometry, the kissing number of a mathematical space is defined as the greatest number of non-overlapping unit spheres that can be arranged in that space such that they each touch a common unit sphere. For a given sphere packing (arrangement o ...
).
[Order in Space: A design source book, Keith Critchlow, p.74-75, circle pattern H]
:
Variations
One variations on this pattern, often called a ''Mediterranean pattern'', is shown in stone tiles with smaller squares and diagonally aligned with the borders. Other variations stretch the squares or octagons.
The
Pythagorean tiling alternates large and small squares, and may be seen as topologically identical to the truncated square tiling. The squares are rotated 45 degrees and octagons are distorted into squares with mid-edge vertices.
A
weaving
Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. Other methods are knitting, crocheting, felting, and braiding or plaiting. The longitudinal ...
pattern also has the same topology, with
octagons flattened
rectangles.
Related polyhedra and tilings
The truncated square tiling is topologically related as a part of sequence of uniform polyhedra and tilings with
vertex figures 4.2n.2n, extending into the hyperbolic plane:
The 3-dimensional
bitruncated cubic honeycomb projected into the plane shows two copies of a truncated tiling. In the plane it can be represented by a compound tiling, or combined can be seen as a
chamfered square tiling.
Wythoff constructions from square tiling
Drawing the tiles colored as red on the original faces, yellow at the original vertices, and blue along the original edges, all 8 forms are distinct. However treating faces identically, there are only three unique topologically forms:
square tiling
In geometry, the square tiling, square tessellation or square grid is a regular tiling of the Euclidean plane. It has Schläfli symbol of meaning it has 4 squares around every vertex.
Conway called it a quadrille.
The internal angle of th ...
, truncated square tiling,
snub square tiling
In geometry, the snub square tiling is a semiregular tiling of the Euclidean plane. There are three triangles and two squares on each vertex. Its Schläfli symbol is ''s''.
Conway calls it a snub quadrille, constructed by a snub operation applie ...
.
Related tilings in other symmetries
Tetrakis square tiling
:
The tetrakis square tiling is the tiling of the Euclidean plane dual to the truncated square tiling. It can be constructed
square tiling
In geometry, the square tiling, square tessellation or square grid is a regular tiling of the Euclidean plane. It has Schläfli symbol of meaning it has 4 squares around every vertex.
Conway called it a quadrille.
The internal angle of th ...
with each square divided into four
isosceles
In geometry, an isosceles triangle () is a triangle that has two sides of equal length. Sometimes it is specified as having ''exactly'' two sides of equal length, and sometimes as having ''at least'' two sides of equal length, the latter versio ...
right triangle
A right triangle (American English) or right-angled triangle ( British), or more formally an orthogonal triangle, formerly called a rectangled triangle ( grc, ὀρθόσγωνία, lit=upright angle), is a triangle in which one angle is a right a ...
s from the center point, forming an infinite
arrangement of lines
In music, an arrangement is a musical adaptation of an existing composition. Differences from the original composition may include reharmonization, melodic paraphrasing, orchestration, or formal development. Arranging differs from orchestr ...
. It can also be formed by subdividing each square of a grid into two triangles by a diagonal, with the diagonals alternating in direction, or by overlaying two square grids, one rotated by 45 degrees from the other and scaled by a factor of
.
Conway calls it a kisquadrille, represented by a
kis
Kis or KIS may refer to:
Places
* Kiş, Khojavend, Azerbaijan
* Kiş, Shaki, Azerbaijan
* Kish (Sumer) (Sumerian: Kiš), an ancient city in Sumer
* Kis, Babol Kenar, a village in Mazandaran Province, Iran
* Kis, Bandpey-ye Gharbi, a village in ...
operation that adds a center point and triangles to replace the faces of a
square tiling
In geometry, the square tiling, square tessellation or square grid is a regular tiling of the Euclidean plane. It has Schläfli symbol of meaning it has 4 squares around every vertex.
Conway called it a quadrille.
The internal angle of th ...
(quadrille). It is also called the Union Jack lattice because of the resemblance to the
UK flag
The national flag of the United Kingdom is the Union Jack, also known as the Union Flag.
The design of the Union Jack dates back to the Act of Union 1801 which united the Kingdom of Great Britain and the Kingdom of Ireland (previously in per ...
of the triangles surrounding its degree-8 vertices.
[.]
See also
*
Tilings of regular polygons
*
List of uniform tilings
This table shows the 11 convex uniform tilings (regular and semiregular) of the Euclidean plane, and their dual tilings.
There are three regular and eight semiregular tilings in the plane. The semiregular tilings form new tilings from their dual ...
*
Percolation threshold
The percolation threshold is a mathematical concept in percolation theory that describes the formation of long-range connectivity in random systems. Below the threshold a giant connected component does not exist; while above it, there exists a ...
References
* John H. Conway, Heidi Burgiel, Chaim Goodman-Strass, ''The Symmetries of Things'' 2008,
* (Chapter 2.1: ''Regular and uniform tilings'', p. 58-65)
*
* Dale Seymour and
Jill Britton, ''Introduction to Tessellations'', 1989, , pp. 50–56
External links
*
*
{{Tessellation
Euclidean tilings
Isogonal tilings
Semiregular tilings
Square tilings
Truncated tilings