Add Area Text to a Fill
Enable the Show Area Text checkbox in the General Settings panel of Fill Settings. When you create the Fill, the Hammer cursor will appear, prompting you to position the area text with a click.
Note: If the fill contains holes, they are subtracted from the fill area.
Note: Favorites of the Text tool can be applied to the text-type items in Dimensions and Labels, and to Fill Text.
The measurement unit and accuracy of the area value are defined in Dimensions (Options > Project Preferences > Dimensions).