Adventures in Triangle World | Paulus Gerdes

…

Starting by presenting some fascinating geometric theorems that have been known since antiquity, Gerdes leads the reader to engage in the world of triangles in an impressive didactic way. The moment I started reading the work, I was counting on doing it only for a few pages to continue later. Every page I read led me to continue reading – an exciting reading, guided by the anxiety of knowing what would happen after the author asked a question that involves the reader in seeking the answer. It is this style that makes to experience the statements presented, which drives reflections and leads to wonderful conjectures about the properties of triangles.

Some of the geometric concepts discussed in this work, such as diatrix, triana, inclined height lines, are from the author's creation, arising by generalizing elements of a triangle already known in Euclidean geometry. We can certainly say that we are facing new results in the field of geometry.

…

Marcos Cherinda Ph.D.

Pedagogical University, Maputo, Mozambique