Reflections

Reflections ﻿Geometer's Sketchpad video representation of reflections  - []  Geogebra video representation of reflections  - []  A reflection is a kind of [|transformation]. It is basically a 'flip' of a shape over the line of reflection. Very often reflecions are performed using coordinate notation as they all are on this page. The coordinates allow us to easily describe the [|image] and its preimage.

>> A reflection in the x-axis can be seen in the picture below in which A is reflected to its image A'. The general rule for a reflection in the x-axis: (A,B) (A, −B) >
 * === Reflection in the x-axis. ===

>> A reflection in the y-axis can be seen in the picture below in which A is reflected to its image A'. The general rule for a reflection in the y-axis: (A,B) (−A, B) >
 * ====** Reflection in the y-axis. **====

> =====** Reflection in the line y = x. **===== >> A reflection in the line y = x can be seen in the picture below in which A is reflected to its image A'. The general rule for a reflection in the y-axis: (A, B) (B, A) >>

Order of symmetry The order of symmetry of a shape is the number of times a shape can be fitted back onto its own outline during a complete turn. A square can be fitted onto its outline four times in a complete turn. The square is said to have a rotational symmetry of order four. A rectangle can be fitted onto its outline twice in a complete turn. The rectangle is said to have a rotational symmetry of order two. 