How many square feet in a tri-axle?

Answer 1

Your question is a bit loaded, and unanswerable as is. If you're trying to figure out the dimensions of a truck bed, you have to keep in mind that square footage is a two dimensional measurement of length plus width, whereas the real world is a three dimensional place, where you also have to account for height and depth. Then the commodity comes into play.... a truck designed to haul asphalt may only have a 15 yard dump body, whereas one to designed mulch might have a 20 or 22 yard body....
High density commodities (such as asphalt, aggregates, sand, etc.) are measured by the ton, as they typically cannot fill up an entire dump body without putting that vehicle over the legal weight limit. Low density commodities (such as mulch) are measured by the cubic yard.. again, we live in a three dimensional world, and if you're trying to figure out how much pea gravel, mulch, whatever you need for a particular project, you also have to account for the depth of the commodity you're laying out.