Envision Geometry-Topic 3
Rigid Motions - answerA transformation that preserves distance and angles
Reflection - answerA transformation that "flips" a figure over a reflection line.
x-axis reflection - answer(x,y) -> (x,-y)
y-axis reflection - answer(x,y) -> (-x,y)
Translation - answera translation is a transformation in a plane that maps all points of a
preimage the same distance and in the same direction
Composition of rigid motions - answera transformation with two or more rigid motions in
which the second rigid motion is performed on the image of the first rigid motion
A composition of reflections across two parallel lines - answer is the same as a
translation that is twice the distance between the parallel lines of reflection in a direction
perpendicular to the lines of reflections.
Rotations - answerA type of transformation that turns a figure around a point by a
certain angle.
90 rotation counterclockwise (270 clockwise) - answer(x,y) -> (-y,x)
180 rotation about the origin - answer(x,y) -> (-x,-y)
270 rotation counterclockwise - answer(x,y) -> (y,-x)
Reflectional symmetry (line symmetry) - answerone half of the figure is an image
reflected across the line of symmetry
rotational symmetry - answerThe ability of a figure to be rotated less than a full circle
and exactly match its original image
line of symmetry - answera line that divides a figure into two halves that are mirror
images of each other
glide reflection - answerthe composition of a reflection followed by the translation in a
direction parallel to the line of reflection.
preimage - answerthe original figure in a transformation
Rigid Motions - answerA transformation that preserves distance and angles
Reflection - answerA transformation that "flips" a figure over a reflection line.
x-axis reflection - answer(x,y) -> (x,-y)
y-axis reflection - answer(x,y) -> (-x,y)
Translation - answera translation is a transformation in a plane that maps all points of a
preimage the same distance and in the same direction
Composition of rigid motions - answera transformation with two or more rigid motions in
which the second rigid motion is performed on the image of the first rigid motion
A composition of reflections across two parallel lines - answer is the same as a
translation that is twice the distance between the parallel lines of reflection in a direction
perpendicular to the lines of reflections.
Rotations - answerA type of transformation that turns a figure around a point by a
certain angle.
90 rotation counterclockwise (270 clockwise) - answer(x,y) -> (-y,x)
180 rotation about the origin - answer(x,y) -> (-x,-y)
270 rotation counterclockwise - answer(x,y) -> (y,-x)
Reflectional symmetry (line symmetry) - answerone half of the figure is an image
reflected across the line of symmetry
rotational symmetry - answerThe ability of a figure to be rotated less than a full circle
and exactly match its original image
line of symmetry - answera line that divides a figure into two halves that are mirror
images of each other
glide reflection - answerthe composition of a reflection followed by the translation in a
direction parallel to the line of reflection.
preimage - answerthe original figure in a transformation
