Term | Definition |
angle of rotation | the angle through which a point is rotated under a rotation |
center of dilation | the point about which a figure is dilated under a dilation |
center of rotation | the point about which a point is rotated under a rotation |
clockwise | in the direction that a clock hand moves |
counterclockwise | in the opposite direction that a clock hand moves |
dilation | a transformation that assigns to each point A on the plane a point A' such that from a given point O, OA = kOA' and A, O, and A' lie along the same line |
half turn | a 180 degree rotation |
image | the resulting figure after a transformation |
invariant point | a point that remains unchanged, or a point that is mapped onto itself, under a transformation |
isometry | a transformation that preserves lengths and angle measures |
line of reflection | the given line of a reflection that is the perpendicular bisector of all segments formed by a point and its image |
map | to assign to each point on a plane its image under a transformation |
reflection | a transformation that maps each point A on a plane to a point A' such that a given line is the perpendicular bisector of line segment AA'. |
rotation | a transformation that maps each point A on a plane to a point A' such that, given a center O, m of angle AOA' is a given angle measure and AO = A'O |
scale factor | the ratio of a length A'B' of a figure's image to the length AB of the original figure under a dilation |
transformation | a function that maps each point to its corresponding point on the plane |
translation | a transformation that maps each point A on a plane to a point A' such that line segment AA' is the same length and has the same direction for all points on the plane |