Angles between faces and edges alingn faces

[klopinRC]

The angles between the edges of the two faces are different than between the faces themselves.

and the second problem is that after aligning the 2 pieces as in the photo, with the faces cut off, the angles shown in the photo change.

Sorry for my English

[HoLyCoW]

That’s because when selecting the faces, it thinks you want to measure the outside angle. When selecting the edges, it’s measuring the inside angle.