2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/71482We study the variation of the Tait number of a closed space curve according to its different projections. The results are used to compute the writhe of a knot, leading to a closed formula in case of polygonal curves.9 pages, 9 figuresGeometric Topology57M25 (Primary); 57M27 (Secondary)text