1988pt 18 - hp 1462
-462 - 462
tdp +21=2 le
mp reason abstractly write an equation to find the value of x so that each
pair of polygons has the same perimeter. then solve.
12x
x+2
12x
x + 5
x + 3
20.
x
+ 4
x
+1
x +
12x
12x

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.