Question

Which type of transformation does not preserve orientation?

Answer 1

Perfect example of "oriented" figure on a plane is the right triangle $\Delta ABC$ with sides $AB=5,BC=3$ and $AC=4$
To introduce orientation, let's position ourselves above the plane and, looking down on this triangle, notice that the way from vertex A to B and then to C can be viewed as the clockwise movement.
Rotation, translation (shift) or dilation (scaling) won't change the fact that the direction$A\to B\to C$ is clockwise.
Use now a reflection of this triangle relative to some axis. For instance, reflect it relative to a line BC. This transformation will leave vertices B and C in place (that is, B'=B and C'=C), but vertex A from being to the left of line BC will move to the right of it to a new point A'
The way $A^{\prime }\to B\to C$ is counterclockwise. That is a manifestation of (1) our triangle has orientation and (2) the transformation of reflection does not preserve the orientation.