Pentagons and Pentagrams: An Illustrated History

Veteran historian of mathematics and gifted expositor Eli Maor has built a distinguished career around exploring single mathematical themes in depth (the number e, the Pythagorean theorem, geometric beauty, …) and tracing their cultural and intellectual reverberations across centuries. In Pentagons and Pentagrams, richly illustrated by Swiss artist Eugen Jost, Maor turns his attention to the five-sided polygon and its starry counterpart, producing an engaging narrative that is at once historical survey, recreational mathematics compendium, and meditation on mathematical interconnectedness. The subject may appear modest: the regular pentagon and the pentagram formed by its diagonals. Yet Maor demonstrates early on that this figure, lacking the immediate symmetry of the square or the hexagon, conceals structural subtleties that have fascinated mathematicians for over two millennia. The internal web of ratios created by the pentagon’s diagonals gives rise to relationships of striking elegance and surprising depth. What seems at first glance geometrically awkward reveals itself as mathematically fecund.