surface inclination with precise values

[Maicol86]

Good morning to all, I apologize early for the trivial question maybe stupid but I can't answer. I should draw a bookcase as in attached photo, but how do I tilt the floor in front view with a precise gradation? use acad 2016 thanks in advance to those who want to answer

 

[MassiVonWeizen]

There are many ways.
the most direct is http://www.cad3d.it/forum1/threads/...ne-e-lunghezza?p=164555&viewfull=1#post164555otherwise draw the straight line then use the wheel command to tilt it
otherwise, if all or almost corners are whole and known set the angle of the polar pointing with these measures and then drawings by activating the aforementioned pointing.

 

[Cristallo]

I'm sorry, but to "line the plan in front view" what do you mean?
are you drawing the front view of the library you brought as an example (so you are drawing in 2d) or talk piano in the sense that you are modeling the various shelves and want to rotate the parallelepiped that represents the shelf?