Visual learning is my thing, I wrap my head around things better when I can see them. Way back when, a mathematician named Oliver Byrnes created a version of Euclid's "Elements."
Euclid's book was to clarify and codify the understanding of geometry. Byrne's edition of Euclid was an attempt to further the clarification by adding color. It was an attempt of explaining by design.
All of Byrne's version has been digitized and can be viewed online.
Knowing that a child of mine will be learning geometry in the future, I look to this book as an option to learn in a different way. That's why the whole book is living on my computer.