72.5 rounded to the nearest whole number

Given the graphed function below which of the following orders pairs are found on the inverse function

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.

Find the interior angle of a regular polygon which has 6 sides