(3,-2) and undefined slope in slope intercept form

The total number of dental clinics total for the last 12 months was recorded

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.

What is fraction that is equivalent to 3/8