2.  Hidden Lines in Tessellations ◦ “Mind’s Eye” – the angle defined by our mind’s eye to help us find the pattern. ◦ Angles are all the same. ◦ These angles help us understand what shapes can and can not tessellate.  Hidden Circles in Tessellations ◦ Tessellations are closely connected to circles ◦ Some regular polygons tessellate and some do not. ◦ If the angle of a regular polygon is a factor of 360 it will tessellate.

4.  Mind’s Eye hidden circles  Circle is where the shapes come together  The sum of the angles at these locations is 360°

8. Hidden Circles in Tessellations

13.  Angle in regular pentagon is 108°

14.  Angle in regular pentagon is 108  108 is not a factor of 360 so a regular pentagon will not tessellate

15. Where are the circles?