The perimeter of a rectangle is (2 lengths) plus (2 widths).
If one side is missing, then it sounds like you still have enough information
to know what the length and the width are. Just take each number and use
the first line up there /\ to calculate the perimeter with them.
I think that the answer is 2, because if you multiply two by each factor in the original photograph then you get the size of the new photograph.
