# Line Symmetry

A figure has
**
symmetry
**
if there is a transformation of the figure such that the image coincides with the preimage.

The
**
line of symmetry
**
(line symmetry or reflection symmetry) of a figure is a line that divides the figure into two congruent parts which are mirror image of each other.

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Example:
**

A square has $4$ lines of symmetry, a parallelogram has no lines of symmetry, and a rectangle has $2$ lines of symmetry.