Unit 4: Transformations Vocab

transformation

a change in the position, size, or shape of a figure

rigid motion

a transformation that changes the position of a figure without changing the size or shape of the figure

preimage

the original figure in a transformation

image

The resulting figure after a transformation

mapping

describes the moving of a figure with a transformation

line of reflection

A line that a figure is flipped across to create a mirror image of the original figure

center of rotation

fixed point a figure is turned about

Line of symmetry

a line that divides a figure into two halves that are mirror images of each other

translation

moves every point of a figure the same distance in the same direction (slide)

reflection

A transformation that "flips" the figure over a line

rotation

a transformation that takes each point in a figure and rotates it a certain number of degrees around a given point

reflectional symmetry

type of symmetry in which there is a reflection that maps a figure onto itself; type of symmetry in which one half of a figure is a reflection of the other half

rotational symmetry

A type of symmetry a figure has if it can be rotated less than 360 degrees about its center and still look like the original

dilation

A transformation that enlarges or reduces a figure by a scale factor.

scale factor

the ratio of the lengths of two corresponding sides of two similar polygons