I have a polygon data set that I created using Arc Collector out in the field. I now need to edit the polygon - preferably in ArcGIS Online, I had a strange extra 'triangle' polygon inside the corner of a rough rectangular shape that I need to delete. I have attempted editing the polygon in ArcGIS Online and have managed to separate the triangle that is a result I think of 'averaging' from the GPS in the mobile device and creating an aberrant extra triangle where it shouldn't be inside the corner of the rectangle. I separated out the triangle and moved it away from the exclosure polygon that I want to keep but it is now showing up as a separate triangle which I can move around, but still seems to be 'connected' to the original rectangular polygon and I can't delete it. When I click on the larger grey vertice of this triangle that I don't want the 'delete' option is greyed out. The triangle shows up as selected in the data table when I select the original rectangle feature.
any ideas what I am not doing correctly? I just want to get rid of this 'sliver' polygon which I have now moved away from the original feature so that I could delete it without interfering with the one I wish to now keep.