In this video you will learn what isometry is and how it applies to transformations in geometry.
Isometry: Used to describe a transformation where the size and orientation are maintained.
Direct Isometry: Orientation stays the same.
Opposite Isometry: Orientation is reversed.
In a transformation, a direct isometry, the order of the points are constant before and after the transformation. In a translation, for example, the order of points stays the same, so it is a direct isometry.
Direct Isometry can be found in: Translations, Point Reflections, and Rotations
In a line reflection, however, an opposite isometry is present and not the direct isomertry. The flipping of the pre-image over a given line reverses the orientation of the image, so it is an opposite isometry.
Opposite Isometry can be found in: Line Reflections