Line reflections

Glide ReflectionsReviewMrs. Erickson

Composition of TransformationsWhen two transformations are performed, one following another, that is called a composition of transformations.

First you get A, then you get A.Glide ReflectionsGlide Reflection: A composition of transformations that consist of a line reflection and a translation in the direction of that line (in either order).ABC:A (1,2)B (5,3)C (3,4)

Reflect in y-axisT0,-4---------------------------T0,-4Reflect in y-axisGlide ReflectionsyxB (5,3)C (3,4)A (1,2)B (-5,3)C (-3,4)A (-1,2)-4B (-5,-1)C (-3,0)A (-1,-2)PQR:P (2,1)Q (4,1)R (3,4)

Reflect across y=xT-3,-3---------------------------T-3,-3Reflect in y-axisGlide ReflectionsyxQ (4,1)R (3,4)P (2,1)Q (1,4)R (4,3)-3P (-2,-1)Q (-2,1)R (1,0)y=xP (1,2)-3ABC:A (1,2)B (5,3)C (3,4)

Reflect in y-axisT5,-5Glide ReflectionsyxB (5,3)C (3,4)A (1,2)B (-5,3)C (-3,4)A (-1,2)-55Not a glide reflection.The translation is not parallel to the y-axis.

B (0,-2)C (2,-1)A (4,-3)6An 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.

IsometryDone!

Did that horn scare you? what about now?