The bottom rectangle is 52 ft by 27 ft.
The top rectangle is 30 ft by 17 ft (calculated as 57 ft - 27 ft - 13 ft = 17 ft).
The connector rectangle is 13 ft by 9 ft (calculated as 30 ft - 21 ft = 9 ft).
total area = 52 ft * 27 ft + 30 ft * 17 ft + 13 ft * 9 ft
total area = 1404 ft^2 + 510 ft^2 + 117 ft^2
total area = 2031 ft^2
weight = 2031 ft^2 * 12 lb/ft^2
weight = 24,372 lb