Someon please help me please

1. what is the formula for finding the vertical distance between two points on a coordinate plane?

15 and 14.7 are 1 apart, so 15 – 14.7 must be 1.

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.