How to add the angle of the sky and the earth to the ID?

The zenith and the earth are set according to personal preferences. Personally, I prefer to leave a centimeter. As for the reservation, it is necessary to read the binding method of the book. I've also seen the VI ordered by riding a horse. If it's a riding order, you don't have to consider the opening. If it is bound or sewn, it depends on the P number of your book and the opening where the paper weight exceeds 40P. You should put 3 mm more. I hope it helps you.