4. What common points can we observe on these images?
Do we often find this in architecture?

5. ARCHITECTURE Session 1 : TESSELLATION
A Tessellation (or Tiling) is when you cover a surface with a pattern of flat shapes so that there are no overlaps or gaps.
overlap = cross each other gap = openning

6. Rectangles
Octagons and Squares
Different Pentagons

7. REGULAR TESSELLATIONS
A regular tessellation is a pattern made by repeating a regular polygon.
List the regular polygons and represent the associate tessellation.
How many regular tessellations are there? Why?

8. The angle sum of a polygon with n sides is :. 180
The angle sum of a polygon with n sides is : 180*(n-2) This means that each interior angle of a polygon measure

10. The angle sum of the interior angles of the regular polygons meeting at a point add up to 360 degrees

11. Semi-regular Tessellations
A semi-regular tessellation is made of two or more
regular polygons. The pattern at each vertex must
be the same!
There are only 8 semi-regular tessellations.
To name a tessellation, go around a vertex and write down how many sides each polygon has, in order ... like " ".
And always start at the polygon with the least number of sides, so " ", not " "

12. 

13. Other Tessellations
There are also "demiregular" tessellations, but mathematicians disagree on what they actually are!
And some people allow curved shapes (not just polygons) so you can have tessellations like these: