# Describing Reflections

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## Reflection

*the line of reflection*.

## Glide Reflection

A glide reflection is a transformation that combines a translation and a reflection. A line segment, $\overline{AB},$ transformed by a glide reflection might look like this. First it is translated to $\overline{A'B'}.$

Next it is reflected in the line of reflection to $\overline{A''B''}.$

A glide reflection could instead be a reflection followed by a translation, because the image created does not depend on the order of the transformations.

## Line Symmetry

A figure is said to have line symmetry if there exists a line such that, when the figure is reflected in the line it is mapped onto itself. In this case, the preimage and image are identical.

The line of reflection in which the figure has line symmetry is called *line of symmetry*. A figure can have more that one line of symmetry. For example, a square has four.

## Exercises

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