Question part points submissions used find an equation of the tangent to the curve at the point corresponding to the given value of the parameter. x = t cos(t), y = t sin(t); t = π

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.