What is e^ln400 equivalent to? how do you know?

The center of the circumscribed circle lies on line segment and the longest side of the triangle is equal to the of the circle.

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.

Joey is asked to name a quadrilateral that is also a rhombus and has 2 pairs of parallel sides.should be his answer