(x +78)
(x-9)
The figure is not drawn to scale

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.

What is the surface area of the sphere?

The area of each triangle is 7 square units. the surface area of the triangular prism is