Since I got such a fast reply to my last post I figured I'd go ahead and post for help on this one. I am stuck this time because I don't understand the depth when V=L (660) x W (660) x D (?)?

---a) If 18 inches of water are evaporated from an artificial lake that is 660 feet long and 660 feet wide, what is the volume of water that evaporated in gallons? b) If annual precipitation adds 9 inches to the lake and annual discharge adds 108, 900 ft2, what would be the net loss of water from the lake in ft3?---