a. Why does the image of ray CA line up with rayCE?
The image of ray CA and CE coincide after rotating because, (rotations preserve rays, or we defined our rotations that way)
b. Why does the image of A coincide with E?
Transformations preserve, (angles, distance, or orientation) so the image of point A and point E are the same, (distance, orientation) along the same ray from C and they have to coincide.
c. Complete the explanation to prove triangle CBA is congruent to triangle CDE.
The rotation would also make the image of B, (coincide, equal) with D. So there is a, (magnitude, rigid motion, translation) that takes CBA onto CDE.
