Geometry Topic 3 Vocabulary

image

a figure resulting from a transformation

line of reflection

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

preimage

the original figure in a transformation

reflection

A transformation that "flips" a figure over a mirror or reflection line.

rigid motion

a transformation that preserves length and angle measure

composition of rigid motions

a transformation with two or more rigid motions

angle of rotation

the number of degrees a figure rotates

center of rotation

the point around which the rotation occurs

rotation

turn

point symmetry

the type of symmetry for which there is rotation of 180 degrees that maps a figure onto itself

reflectional symmetry

a symmetry for which a reflection maps the figure onto itself

rotational symmetry

when a figure maps onto itself after a rotation of less than 360 degrees