When a point or figure on a coordinate plane is moved by sliding it to the right or left or up or down, the movement is called a translation. The figure is translated from one position to another.
Emphasize the basic properties of translations:
1. Lines are taken to lines, and line segments to line segments of the same length (this property states that choice C is incorrect).
2. Angles are taken to angles of the same measure.
3. Parallel lines are taken to parallel lines and orientation of the figure remains the same (this property states that choice B is incorrect).
4. The image of a figure under a translation is always congruent to the preimage (this property states that choice A is incorrect).
Answer: correct choice is D (prove that using property 1 and definition of translation).
