They correspond to rigid motion, with no stretching or squishing or morphing.
它们对应于刚性运动 没有拉伸 挤压或变形。
英语百科
Euclidean plane isometry
(重定向自Rigid motion)
In geometry, a Euclidean plane isometry is an isometry of the Euclidean plane, or more informally, a way of transforming the plane that preserves geometrical properties such as length. There are four types: translations, rotations, reflections, and glide reflections (see below under classification of Euclidean plane isometries).