These topics were my main focus of teaching at UNCC, due to the needs of the mathematics department of UNCCharlotte.
I have gathered the material on these topics during my time at UNCC Charlotte as professor of mathematics.
After I had to retired for health reasons, I could still supplement these notes and publish several books, on barnes and noble, amazon, draft2digital.
There is a series ” A Course in Old and New Geometry” with six volumes,
All volumes are self-contained. I recommend the most important
Volume II: Basic Euclidean Geometry
https://draft2digital.com/book/3069870
https://www.barnesandnoble.com/w/volume-ii-franz-rothe/1147943021?ean=9798231094943
Some notes about the geometry course are to be read here
“D:\collection-en\courseoldandnew.pdf”
My work in graph theory, number theory, modern algebra and problem solving is summed up in the four books
“Classics in Graph Theory”
“Essays about Number Theory: From Classical Topics to New Problems”
https://www.barnesandnoble.com/w/essays-about-number-theory-franz-rothe/1144560432?ean=9798369414354
“Essays about Modern Algebra”
“My Invitation to Mathematical Problems: Computations, Solutions, Proofs and Insights”
To search the entire list of my books on barnes and noble
https://www.barnesandnoble.com/s/%22Franz%20Rothe%22?
Several pages of this book can be read on the website
A few other books are shown on the website
Beyond my Career 