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How do I combine (join?) two overlapping polygons to determine the combined area they cover in ArcGIS 10?

I am sure the Geoprocessing tools can do it, but just how eludes me.

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I think this Question needs to have a diagram added to make what it is asking clear. – PolyGeo Dec 30 '13 at 9:38
up vote 5 down vote accepted

You're looking for the Dissolve tool - if all of your polygons are in the same featureclass/layer just run it and then use the Field Calculator to determine the area.

If your polygons are in different featureclasses, run the Merge or Append tool first.

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Thanks for the reply. I know I'm nearly there not just quite yet. I have merged the polygons, but I can't seem to figure out what the Dissolve tool does. The merged polygon's attribute table only features the individual areas for the original polygons... – Tomm Apr 16 '13 at 0:38
Ahh... got it! Thanks heaps!!! – Tomm Apr 16 '13 at 0:41
Hi Tomm: If Radar's answer solved your question, you may want to upvote it in addition to accepting it. – Dan C Apr 16 '13 at 1:35
Okay, done..... – Tomm Apr 16 '13 at 3:43
I"m actually surprised that's the answer. If you're looking for the area of overlap of 2 overlapping polygons, I would think that Intersect would be your tool of choice. – Clickinaway Apr 19 '13 at 11:46

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