No, it’s easier to demonstrate using your actual file.
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Make a duplicate of your roof section
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Move and align duplicate as shown here (use the Two-Point Rotate/Scale tool):
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Convert the cutout to a path.
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Using the node edit tool break the rectangle at this corner then extend one side as shown
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Duplicate then move as shown:
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Delete the duplicated roof section as you don’t need this any more.
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Trim the line you extended before.
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Close the path that represents the tab, ungroup your main profile then weld the tab to the main profile. (When I did this it wasn’t quite perfect).
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In this case you can just delete the offending node to give this:
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Repeat for the others.
Someone might have a better way but that’s what I came up with. Hope it helps.