In Wakefield, the library is 12 miles due south of the courthouse and 5 miles due west of the community
swimming pool. What is the distance between the
courthouse and the community swimming pool?

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.