Geometry H 4.4-4.5 Check-up

A congruence transformation is a transformation that preserves the shape and size of a figure, meaning the pre-image and image are congruent. Examples include translations, rotations, and reflections.

A reflection in the x-axis transforms the point (x, y) to (x, -y).

A scale factor of k < 1 indicates a reduction in size.

A scale factor of k > 1 indicates an enlargement in size.

If the scale factor k is less than 1, it is a reduction. If k is greater than 1, it is an enlargement.

A rotation of 90 degrees counterclockwise transforms the point (x, y) to (-y, x).

A rotation of 180 degrees transforms the point (x, y) to (-x, -y).

A rotation of 270 degrees counterclockwise transforms the point (x, y) to (y, -x).

Two reflections in intersecting lines result in a rotation about the point of intersection, with the angle of rotation being twice the angle between the two lines.