The LC1 armchair by Cassina, designed by three great masters of architecture and design, Le Corbusier, Pierre Jeanneret and Charlotte Perriand, is a cult of international design. A light and compact seat, designed and presented in 1929 at the Salon d'Automne. Like all of Le Corbusier's works, the LC1 armchair also derives from an in-depth study of body posture and, in this specific case, it offers itself as a perfect support for composed relaxation that predisposes to conversation. The balance between form and function relies on the use of Modulor, a system based on the typical measures of the human body and on a mathematical language based on the proportions of universal harmony. Its perfect compositional simplicity, adaptable to different contexts.