Use the slider to rotate pentagon ABCDE about the center of rotation, R. The angle through which the pentagon is rotated is , represented by the variable

, where

. At what values of

does pentagon

coincide with pentagon

? Enter the values in the table. For each value of α that you enter, enter the vertex that coincides with vertex

.

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled

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.

Select the correct answer and solve for y