Conflicting measurement units with buffer ftools
I have a shapefile as input. How could I create a circle with a radius of exactly 500 meters, using QGIS?
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
If you need a polygon that is like a circle, you can select a point, then use Vector->Geoprocessing Tools->Buffer(s). Set the buffer distance to the desired radius.
Note that it will be a polygon when you save it to a shapefile. It'll look round at some scales though :-)