Answer:
4 lines of reflection can the combined figure reflect onto itself.
Explanation:
Given Square ABCD and square EFGH share a common center on a coordinate plane and is parallel to diagonal.
We have to find that how many lines of reflection can the combined figure reflect onto itself.
Line of reflection is the line through which the figure will reflect to give a mirror image i.e the midway line between the pre-image and its image reflection. In the figure drawn in attachment according to given question we see that the line passes through the center of one square which is the diagonals of other square reflect the given figure onto itself.
Hence, there are 4 lines of reflection i.e 4 lines of reflection can the combined figure reflect onto itself.