Recall the definitions of all the transformations that you know.
It is not a rigid motion.
Practice makes perfect
We are asked to say how a dilation is different from other transformations. Let's recall the definitions of different transformations that we know, and compare them with the way dilation work.
Translation
A translation is a transformation in which a figure slides but does not turn. Every point of the figure moves the same distance and in the same direction.
Reflection
A reflection is a transformation in which a figure is reflected in a line called the line of reflection. A reflection creates a mirror image of the original figure.
Rotation
A rotation is a transformation in which a figure is rotated about a point called the center of rotation. The number of degrees a figure rotates is the angle of rotation.
Dilation
A dilation is a transformation in which a figure is made larger or smaller with respect to a point called the center of dilation. In a dilation, the angles of the image and the original figure are congruent.
Conclusion
Notice that dilation is the only transformation that changes the size of the figure. Transformation that preserves length and angle measure is called rigid motion. Examples of this kind of transformation are translations, reflections, and rotations. However, dilation is not a rigid motion.
