(I'll assume that your table is named [AREAS].)
The trick here is to create a saved UNION query named [AreaDataForPieChart]...
SELECT "DONE" AS PieCategory, [DONE] AS PieValue, [AREA] FROM [AREAS]
UNION ALL
SELECT "REMAIN" AS PieCategory, [REMAIN] AS PieValue, [AREA] FROM [AREAS]
...returning...
PieCategory PieValue AREA
----------- -------- -----
DONE 100 AREA1
DONE 200 AREA2
DONE 200 AREA3
REMAIN 200 AREA1
REMAIN 300 AREA2
REMAIN 700 AREA3
...and base the pie chart on that.
Start by creating a Report based on the [AREAS] table, and display [AREA] in a text box:
Now add a Chart control to the Detail band of the report. When prompted, choose the saved query we created above
Choose [PieCategory] and [PieValue] as the columns for the chart
Choose "Pie Chart" as the chart type
The default data layout will work fine because of the order of the columns in our query
Tell the report to link the chart to the main report by using the [AREA] fields
Give the chart a meaningful title, then click the "Finish" button.
Now preview the report. It should look something like this: