6 ) hey pls help me with his I have the answers all I need is to show the work Consider angle B in the diagram below . What is the length of “opposite side” to angle B?

a

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.