Answer:
CD
Step-by-step explanation:
Given that quadrilateral abcd is congruent to quadrilateral efgh
This means in the same order we have to take corresponding sides and angles and they would be equal.
Hence we have
angles : A =E: B =F: C=G:D=H
Sides: AB = EF:BC=FG:CD=GH:DA =HD
Hence from these we can conclude that CD =GH
So answer is CD
