Teaching area for graphs
A classroom discussion about the content of a graph (e.g. how area can be misused in graphs) would be a good beginning, and then an exploration of why the topic might need to be reported.
Using a well-constructed graph as an example, hold a class discussion about the key aspects of a correct graph. Discuss the appropriateness of titles and labels. Emphasise that any use of area needs to be proportional to the value or frequency being represented.
Students could be introduced to the discussion points for the area in graphs on public housing costs, either to work on individually or as a whole-class activity.
Alternatively, you may be able to find other examples of misleading area graphs that would appeal to your class and conduct a similar activity.