Final answer:
A reflection is a transformation that does not preserve orientation.
Step-by-step explanation:
In mathematics, a transformation that does not preserve orientation is called a reflection. A reflection is a transformation that flips a figure over a line, called the line of reflection. When a reflection is performed, the size and shape of the figure remain the same, but the orientation of the figure is reversed.
For example, if you draw a triangle on a sheet of paper and then reflect it over a vertical line, the resulting image will be congruent to the original triangle but will have a reversed orientation.