Becca Stockford Lehman. Tessellate: to form or arrange small squares or blocks in a checkered or...
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Transcript of Becca Stockford Lehman. Tessellate: to form or arrange small squares or blocks in a checkered or...
TessellationsTessellate: to form or arrange small
squares or blocks in a checkered or mosaic pattern
Comes from the Latin word tessella which refers to the small square pieces used in mosaics
Another word for tessellation is tiling
Tiling: filling a flat space in with individual tiles ensuring there are no gaps or overlaps
Regular TessellationsTessellations made up of congruent regular polygons
Arrangement of nonoverlapping polygonal tiles surrounding a common vertex is called a vertex figure
Three regular polygons can tessellate in the Euclidean plane
-triangles
-squares
-hexagons
(180 (N-2))/N is the angle at each vertex of a regular polygon, N being the number of sides
Semi-regular TessellationsSemi-regular tessellations are formed
from regular polygons
The arrangement at every vertex point is identical
Unlike regular tessellations you can use more than one regular polygon
There are eight semi-regular tessellations
Naming TessellationsTo determine the name of a
tessellation-
(1)Look at a vertex within the tessellation
(2)Look at one of the polygons touching that vertex
(3)Count the sides of that polygon and that is the first number
(4)Repeat until you have included the sides of every polygon touching the vertex
Examples with Semi-regular Tessellations
3.3.3.3.63.3.3.4.4
3.4.6.4
4.6.12
3.6.3.6
3.3.4.3.4
3.12.12
4.8.8
Other TessellationsTiling's with irregular polygons – as
long as the polygons are congruent the plane can be tiled with-any triangle tile-any quadrangular tile, convex or not-certain pentagonal tiles -certain hexagonal tileCan also tile a plane with nonconvex
polygons
Heesch’s Tile- every tile is identical but appear in positions that are non-identical
Aperiodic tilings – do not repeat themselves
Honeycombs and crystals- 3-dimensinal tessellations
Escher Tilings Maurits Cornelius Escher: artist who
created artistic tilings
Based on modifications of known tiling patterns
Creation of TessellationsUse of reflections and rotations
Transitional symmetry : moving the shape over some unit(s)
- 2 types, up-down and left-right
Glide symmetry: combination of translation and a reflection
Tessellations in architectureFrieze Groups- Frieze is a narrow band along
the top of a wall which in the past were decorated with repeating geometrical patterns
Seven groups
(1) Hop: only translations
(2) Sidle: translations with reflections in vertical lines
(3) Jump: translations and one horizontal reflection
(4) Step: translations and glides
(5) Spinning hop: translations with rotational symmetries of 180 degrees
(6) Spinning sidle: translations, glides, vertical reflections and rotational symmetries of 180 degrees
(7) Spinning jump: translations, vertical reflections, one horizontal reflection and rotational symmetries of 180 degrees
Can you name this tessellation? What type of tessellation is it (regular, semi-regular, other)?
3.4.3.12 cannot tessellate over infinite plane (other)
Sources:
Books-
Mathematics 1001. Dr. Richard Elwes pg 108-114
Mathematical Reasoning for Elementary Teachers. Calvin T. Long and Duane W. DeTemple, pg 861-868
Websites-
http://mathforum.org/sum95/suzanne/whattess.html
http://www.mathsisfun.com/geometry/tessellation.html