Find the measure of each angle indicated

Find the value of x for which line a is parallel to line b

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.

8litres of paint can cover 129.6 m². how much paint is required to paint an area of 243m²?