Regular hexagon FGHIJK shares a common shares a common center with square ABCD on a coordinate plane .

Step-by-step explanation: As shown in the attached figure, regular hexagon FGHIJK and square ABCD shares common centre on the co-ordinate plane and AB || FG.

We are to find the line across which the combined figure will reflect onto itself.

In the attached figure, we see two lines which are yellow in colour. We can easily detect that the figure will be reflected onto itself if these two lines acts as a mirror separately.

Hence these yellow lines are the required lines."