Final answer:
Tanya should use a reflection to change the orientation of a figure without changing the orientation of the vertices.
Step-by-step explanation:
The transformation that Tanya should use to change the orientation of a figure without changing the orientation of the vertices is a reflection. A reflection is a transformation that flips a figure over a line, called the line of reflection. The vertices of the figure will stay in the same location, but the figure will be flipped.