Movements

A movement (also called an isometry or rigid motion) in space is a transformation that preserves distances between all points. That is, for any two points $A$ and $B$, the distance between their images after the movement is the same as the distance between $A$ and $B$.

Important properties

• Movements preserve lengths, angles, and shapes.

• Examples of movements include translations, rotations, reflections, and glide reflections.

• Movements can be combined to form new movements (composition).

• Movements are reversible: every movement has an inverse movement.