Well, if GHJK is just a smaller version of LMNP, then they are proportional to each other.
It's saying that the small rectangle is 2 square inches. You can tell then that it is a 2in x 1in rectangle. You know that the ratio of between the long sides is 2:10. If we say that the shorter sides of the larger rectangle is x. Then we should know that the 2:10 proportionality will be true for 1:x. Well, 2 is to 10 as 1 is to 5. So the big rectangle has side lengths of 10 in and 5 inches. I'll let you go from there.
