Symmetry:  The Art of Mathematics		Hillyard/Rasmussen

Class 5 Outline

I) Go over assignment 4


II) Construction Quiz


III) Rotations 

	A) Group exercises
		1) General definition of what a rotation is: groups report
		2) Search for some examples online.
		3) Groups report on their favorite site and why.
		4) Groups experiment making rotations.
		5) Groups share rotations.

IV) Break


V) Introduction to “rigid motions” of the plane
 
	A) Motions of plane that preserve distance.
	1) Group exercise: do rotations preserve distance
	2) Group exercise: do reflections preserve distance
	3) Group exercise: can they think of another rigid motion that preserves distance?

	
VI) Rigid motions revisited

	A) Combining two rigid motions M and N
		1) choosing our convention who goes first

	B) Instructor try reflection in horizontal line first, then reflection in vertical line.
		1) Groups: what happened?


VII) Homework
	
	A) Hand out assignment 6 due Wednesday April 12, 2006.