This is wrong. Acres are defined as the area encompassed by a particular set of lengths, but acres do not have specified widths and lengths because it is a unit of area, not of width or length. Acres can be any shape. They do not have to be rectangular.

The page appears to talking about the Apex Regional landfill near Las Vegas, Nevada, which has an _area_ of 2200 acres. Though you'd never know it because the page has no citations anywhere.