Question

Priya tried to translate triangle ABC by the directed line segment from D to E. She knows something went wrong because the image isn’t congruent to the original figure.
What is one idea that Priya probably understands about translations?

Answer 1

Answer:

When we do a translation, all the translated points must be translated in parallel (between them) lines. (this would mean that all our points suffer the same translation)

Here we can see that the lines BB´ and AA´ are parallel, but the line CC´ is not parallel to the other two. So the distance of the translation is constant, but the direction is not the same for all the points.

Then this is not a translation of all our triangle, because different points suffered different translation operations, this is what caused the triangles ABC and A´B´C´ to not be congruent.