I have a buffer of an original line shapefile, now a polygon file, and want determine what percentage that buffer occupies in polygons from another poly shapefile. I thought either intersect or union was the way to go, but I can't seem to get the numbers to work out. I know the total area of the buffer by running statistics on the field. And I have calculated geometry on the output files, The problem is that the area of the union/intersect polys are much higher than the original buffer area. Perhaps in the union I am inadvertently including both sets of polygons in the calculation? But in the intersect, I don't understand why the total area of the original buffer is much lower than the intersect output. Any suggestions? Am I at least on the right track on the procedure, should both of these overlays work or just one or the other?