A tessellation is a way to tile
a floor (that goes on forever) with shapes so that there is no
overlapping & no gaps. A puzzle is a tessellation! The shapes were weird.
Example: |
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REGULAR TESSELLATIONS:
- RULE #1: The
tessellation must tile a floor (that goes on forever) with no
overlapping or gaps.
- RULE #2: The tiles
must be regular polygons - and all the same.
- RULE #3: Each
vertex must look the same.
What's a vertex?
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where all the "corners"
meet! |
What can we tessellate using these
rules?
Triangles? Yep!
Notice what happens at each
vertex!
The interior angle of each
equilateral triangle is 60 degrees.....
60 + 60 + 60 + 60 + 60 + 60 = 360 degrees
Squares?
Yep!
What happens at each
vertex?
90 + 90 + 90 + 90 =
360 degrees again!
So, we need to use
regular polygons that add up to 360 degrees.
Will pentagons work?
The interior angle of a pentagon is
108 degrees. . .
108 + 108 + 108 = 324
degrees . . . Nope!
Hexagons?
120 + 120 + 120 = 360
degrees Yep!
Heptagons?
No way!! Now we are
getting overlaps!
Octagons? Nope!
They'll overlap too. In fact, all
polygons with more than six sides will overlap! So, the only regular
polygons that tessellate are triangles, squares and hexagons!
SEMI-REGULAR TESSELLATIONS:
These tessellations are made by using two or
more different regular polygons. The rules are still the same. Every
vertex must have the exact same configuration.
Examples: |
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3, 6, 3,
6 |
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3, 3, 3, 3,
6 |
These tessellations are both made up of
hexagons and triangles, but their vertex configuration is different.
That's why we've named them!
To name a tessellation, simply work your way
around one vertex counting the number of sides of the polygons that form
that vertex. The trick is to go around the vertex in order so that the
smallest numbers possible appear first.
That's why we wouldn't call our 3, 3, 3, 3, 6
tessellation a 3, 3, 6, 3,
3!
Here's another tessellation
made up of hexagons and triangles.
Can you see why this isn't an
official semi-regular tessellation?
It breaks the vertex rule! Do
you see where?
Here are some tessellations using squares
and triangles:
3, 3, 3, 4,
4 |
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3, 3, 4, 3,
4 |
Can you see why this one won't be a
semi-regular tessellation?
MORE SEMI-REGULAR
TESSELLATIONS
What other semi-regular tessellations can you think of?
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