Image rotation with axis

My compliments on the many features of the GIMP program.
But for the technical activity that I carry out I find myself some technical documents that have been appropriately scanned.
With the effect that they are rotated with respect to the X-Y axes and you have to try to make rotations by hand.
It would not be advisable to insert three points of a title block or a square to have the correct rotation.

Not too clear what the actual problem is. Two ways to fix rotations:

  1. Using the Rotate tool:
    • Set to Corrective mode
    • Make it display guides (Number of lines for a grid)
    • Acting on the canvas will rotate the guides and not the image
    • Align the guides with whatever should be horizontal/vertical
    • Apply the rotation
  2. Using the Measure tool
    • Measure something along a feature of the image that should be vertical/horizontal
    • Hit the Straighten button in the Tool options

Unless you are talking about perspective distortion (but this doesn’t happen with a scanner, just with photos taken with an angle), in which case the Perspective tool also has a “Corrective” mode.