In this web page, the accessible version of Area Model Introduction is embedded in the iframe. Below, in blue, is the copy of the sim's structured Parallel Document Object Model, or PDOM. As you interact with the visual sim in the iframe with either a keyboard or mouse, the descriptions for the sim automatically update on the right, key dynamic elements will be highlighted like this. Any alerts set on an element with an "aria-live" attribute will be displayed in the activity log, with the most recent interactive alerts first.