From the basic principle to the actual dc generator, where are the 'coil loops'?
Ignore Fig 4.7, it's only a kind of schematic, showing teh electrical connections not the physical reality of the coil.

Looking at Fig 4.9 and taking coil A as you asked, it appears as a tiny circle in slot 1, and another tiny circle in slot 3. So it is going into he page in slot 1, and coming out of the page in slot 3 (or vice versa). The other two circles in those slots represent coil C.

EDIT : see comment for how Fig 4.9 actually works. And rather than try to keep up with the evolving question, I'll point out that when you analyse the windings in the photo you'll find the coils are arranged in sets of 3 (every third coil is connected together) - you'll need to learn a bit about 3 phase AC electricity before you understand this one.