Answer:
d. triangle 1 and triangle 4
Explanation:
a. 4 can be shown congruent to 3 by a single rotation
b. 3 can be shown congruent to 2 by a reflection
c. 2 can be shown congruent to 1 by a translation
d. 1 can be shown congruent to 4 by both a reflection and a rotation. This is the pair of triangles that requires more than a single rigid motion to show congruence.