Geometry Illuminated: An Illustrated Introduction to Euclidean and Hyperbolic Plane Geometry (Mathematical Association of America Textbooks)

I'm a nerd who likes to read math books when on business travel. Usually they help me fall asleep faster. So I was pleasantly surprised. Instead of putting me to sleep, the author took me on a journey through the foundational concepts of geometry in a way that was both engaging and informative. The author, clearly passionate about the subject, has a knack for explaining complex topics with clarity and simplicity, making geometry interesting.

I didn't have any background in geometry besides what they taught us in high school, and I was able to understand this book very well. It takes you into the different types of geometry that I didn't even know existed. A very neat topic to study if you are interested in studying mathematics at the college level.