Two plane figures are called congruent if one can be moved by a sequence of translations, rotations and reflections so that it fits exactly on top of the other figure.

The example above involves a translation of 5 to the right and 1 up. The two hexagons are congruent.

In the second diagram the second hexagon has been obtained from the first by a rotation of 270 ° clockwise about $$B$$ and then a translation of 1 unit to the right. Note that the orientation of the shape has not changed. Once again, the two hexagons are congruent.