Created a MoI map overlay trace of a fruit orchard from a google earth satellite map. MoI is so easy to use.
Used all polylines, with each block assigned a closed polygon.
Used Object names for some descriptions. May also use some colors.

Did a google search for "polygon area algorithm javascript."
For plain, plane, non-intersecting polygons, there is a simple algorithm for
calculating the area of the closed polygon. Top View eliminates the Z coordinates.
The algorithm seems to have several names, "the surveyors formula," "the shoelace algorithm," Gauss's area formula,"
and Greens theorem.

I think I will try to make a simple script to calculate the area of a polygon. It seems fairly easy. Just need the X,Y coordinates for all of the vertices,
in order starting from one vertex. The user would select one polygon at a time.
Also would need a baseline distance for the Map.
A qtr_qtr section contains 40 acres, and is 1320 feet on a side.

The script would only work for polygons, not for Nurbs curves in general.