Aaron,
there's no reason to feel sorry
Maybe you can upload screenshots before and after filleting, to make things clearer.
Also, what is your current LibreCAD version and operating system?
There is a difference between the rectangle tool, which creates a polyline and a 'handmade' rectangle with 4 single 2-point lines. This has changed sometime in 2.0 release iirc. Before that, the rectangle tool created 4 single lines too, with no relation between the lines.
Filleting a polyline always trim the lines because the polyline is a container entity and the fillet has to be inserted in the chain of entities.
But filleting simple lines is influenced by the Trim checkbox. When the checkbox is checked, the lines should be trimmed to match with the fillet. When it is unchecked, the fillet is created, but the lines should be untouched. On no account they should be deleted by the fillet tool.
Armin
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