1. Glide Reflections
Review
Mrs. Erickson

2. Composition of Transformations
When two transformations are performed, one following another, that is called a composition of transformations. First you get A’, then you get A’’.

3. Glide Reflections
Glide Reflection: A composition of transformations that consist of a line reflection and a translation in the direction of that line (in either order).

4. Glide Reflections ΔABC: A (1,2) B (5,3) C (3,4) Reflect in y-axis
C’ (-3,4)
C (3,4)
B’ (-5,3)
B (5,3) -4
A’ (-1,2)
A (1,2)
C’’ (-3,0) x
B’’ (-5,-1)
A’’ (-1,-2)

5. Glide Reflections ΔPQR: P (2,1) Q (4,1) R (3,4) Reflect across y=x
Reflect in y-axis -3
Q’ (1,4)
R (3,4)
R’ (4,3)
P’ (1,2) -3
Q’’ (-2,1)
P (2,1)
Q (4,1) x
R’’ (1,0)
P’’ (-2,-1)
y=x

6. Glide Reflections ΔABC: A (1,2) B (5,3) C (3,4) Reflect in y-axis-5 x
C’’ (2,-1)
Not a glide reflection.
The translation is not parallel to the y-axis.
B’’ (0,-2)
A’’ (4,-3)

7. Isometry An isometry is a transformation that preserves distance.
Direct isometry: preserves distance and orientation.
Opposite isometry: preserves distance but changes the orientation from clockwise to counterclockwise, or counterclockwise to clockwise.

8. Done!
Did that horn scare you?
… what about now?