Refer to the diagram. A drainage system has a concrete inlet facility that incorporates a 10` x 6` x 6″ headwall. A 3` inlet pipe and 2 identical 6` x 6` x 6″ wingwalls. How much concrete should be ordered? Do not include waste.

Refer to the diagram. A drainage system has a concrete inlet facility that incorporates a 10` x 6` x 6″ headwall. A 3` inlet pipe and 2 identical 6` x 6` x 6″ wingwalls. How much concrete should be ordered? Do not include waste.