A group of students formed a circle during a game. The circumference of the circle was about 43.96 feet and the diameter of the circle was 14 feet what best represents the value of n.

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.