Géométrie du nombre d’or

With the aid of a simple piece of rope along which a knot was tied after every cubit (approximately 52cm, from the elbow to the fingertips), the ancient cathedral builders left their mark on the ground: circular arcs, straight lines, perpendicular lines, mandorlas, spirals and other wonderful outlines to define and position architecture and its decor. This rope was also used to determine the ideal proportions which would make constructions more beautiful and moving. It is only with the ruler and compass, which replaced the rope, that Robert Vincent reveals the secrets of these builders, as much through the art of the outline as its use according to the divine proportions of the golden number. These outlines, which are thrilling to recreate yourself, do not require any mathematical knowledge, for the young they are a source of enjoyment and imagination, they lead us into a universe of emblematic figures and that of the golden number through human endeavour, from the pyramid of Khufu to that of the Louvre by Le Corbusier, the Tarot of Marseille or the official ball used in football. The author then offers us a number of previously unseen geometric curiosities and others such as the duplication of the cube or the quadrature of the circle (with the square of Mercury or Leonardo de Vinci’s canon of proportion), which bring them within our reach! TABLE OF CONTENTS Foundation outlines Graphic determination of the golden number and its measurement Pentagons and the dynamics of five Geometric figures which the golden number influences Platonic bodies The golden number in human work Geometric curiosities