ebook exercise

exercise book - exercise 48

the exercise is about geometries
I think that between teeth 14-13 is geometry I and 13-12 geometry III, but in the answers there is solution : 14-13 geometry IV and 13-12 geometry IV.
Can you please check?

These are the answers in the book and they are correct:
Between 1.4 and 1.3 there is a geometry II
Between 1.3 and 1.2 there is a geometry III