[Qgis-user] Calculating polygon area

[Lynkos]

Dear all, here I am back with one of my usual "newbie" questions which I'm
sure has such a simple answer that I already feel embarassed in advance!
Here goes anyway...
I'm trying to calculate the area and perimeter length of a polygon
shapefile. Using the QGIS measuring tool and clicking along the outline of
the polygon, I get an answer of approximately 663 km area with a perimeter
of about 110 km... and those values seem about right.
So what's the problem? The problem is that if I do the same using the Field
Calculator, or the "Extract Add Geometric Columns" vector tool (not sure if
the name is right, I'm using the Italian version), I get completely
different answers: an area of 0.072189 and a perimeter of 1.13297 (not even
sure in what units). The layer units are set to metres and reprojection is
disabled. Help!! What am I doing wrong!?
I could of course simply continue using the measuring tool, but I have a
lot of polygons to calculate and some are very complex.
Thanks for your usual patience, Sarah.



-- 
Con altri occhi - parole e immagini dalla parte della natura
www.lynkos.net
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