a line on which a figure can be folded into two parts that are congruent mirror images of each other.

The reflection or mirror line of a reflection transformation.

a line that divides a figure so that its reflection coincides with the original

A line that divides a figure into two halves that are mirror images of each other. Line segment: A part of a line with two endpoints.

A line that divides a figure into two parts, each a mirror image of the other.

A line that separates a figure into halves. Each point in one of the halves of the figure is the same distance from this line as the corresponding point in the other half.

A line that divides a figure into two congruent halves that are mirror images of each other. A test to determine if a figure has line symmetry is to fold the figure along the supposed line of symmetry and see if the two halves of the figure are identical.