A seed company planted a floral mosaic of a national flag. The perimeter of the flag is 2280 Determine the flag's width and length if the length is 300 ft greater than the width. The flag's width is
nothing ft. Its length is
nothing ft.

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.