[OpenLayers-Users] area enclosed by linestring

[Jim White]

Hi,

I use this to calculate the number of acres enclosed by a linestring:

ring = new OpenLayers.Geometry.LinearRing(geometry.getVertices());
area = ring.getGeodesicArea(new OpenLayers.Projection("EPSG:900913"));
area = Math.floor(Math.abs(area*0.000247105381));

The calculated area consistently produces results that are 2-3% too 
small. Is this an error in my code or is my data the problem?

Thanks,
Jim White