The book is still in progress [0]. For example, the introduction has yet to be written, which presumably would answer some of these questions about the intended audience.

The author also has books [1] on tangentially related subjects, several with a good amount of overlap in material.

[0] https://www.cis.upenn.edu/~jean/gbooks/geomath.html

[1] https://www.cis.upenn.edu/~jean/gbooks/home.html