Symmetry:  The Art of Mathematics                  Hillyard/Rasmussen

 

Class 17 Outline

 

I) Hand back assignment 12 & 14

           

 

II) Review of two-dimensional band ornaments: summary of our last class

 

A)   generated lots of new examples using square & hexagonal grids

          B) examples we found added to our table of previous examples:

         

Example

Grid type

Least restrictive

 Rotations

Reflections

Glide Reflections

Example 1

Rectangle

R(360)=I

r(v)

None

Example 2

Rectangle

R(360)=I

None

Yes

Example 3

Rectangle

R(180)

R(360)=I

r(v), r(h)

None

Example 4

Rectangle

 

R(180)

R(360)=I

r(v)

Yes

Example 5, we do not have an example of this yet example as drawn in class does not work

Rectangle

R(180),

R(360)=I

None

 

Yes

Example 6

Parallelogram

(we used a rectangular grid in class)

R(180), R(360)=I

None

None

 

Example 7

Parallelogram

R(360)=I

None

 

None

Example 8

Square

R(90),R(180), R(270),R(360)=I

r(v), r(h)

None

 

Example 9

Square

R(90),R(180), R(270),R(360)=I

None

None

Example 10

Square

R(90),R(180), R(270),R(360)=I

r(v), r(h)

Yes

Example 11

Hexagon

R(60),R(120), R(180),R(240), R(300),R(360)=I

r(v), r(h)

 

 

Example 12

Hexagon

R(60),R(120), R(180),R(240), R(300),R(360)=I

None

 

 

 

 

III) Go over Assignment 15

 

A)   Teams: choose one person to share their example in 1(a) on         white board

1)    team answer to 1(b)

2)    team answer to 1(c)

B)   Teams: choose one person to share example for problem 2 on white board

C)  Teams: choose one person to share example for problem 3 on white board

 

 

IV) Classification of two-dimensional band ornaments:  the last pieces

 

A)   Add our examples from homework assignment 15 to above table

 

B)   The remaining examples:  instructor to do

 

C)  Add the last examples to the table:  hand out visual presentation from Washburn & Crowe (page 61)

 

D)  Hand out the flow chart from Washburn & Crowe (page 128)

1)    Team exercise:  teams use the flow chart to find the type (classification name) and also find what example it is on our table of examples

2)    Teams report

 

 

 

 

 

 

Outline 17  continued

 

V) Symmetry Fest

          A) rules

          B) Tournament

                   1)round one

                   2) round two

                   3) final round

 

 

VI) Break

 

 

VII) UWB course evaluation

 

 

VIII) Quiz 2 on Wednesday 5/24

 

          A) Review:  what will be covered & what you need to know