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.

**Direct Isometry:**

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

**Opposite Isometry:**

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