You can now perform area calculations in Tableau. This is great for calculating the area of small polygons such as parks, building plots and more. be careful though, over large geographies the calculation doesn't compensate for the curvature of the earth so it's only an estimate.
Tableau release notes "In 2020.2, we're introducing the Spatial Area function. Use the Spatial Area function to find the area of any polygon in a geographic role. For more information."
Connected authoring for web edit: New in Tableau 2021.2