A third guideline for a ruled surface: the equal distribution

[EN] The figures analyzed in the thesis “Graphic control surfaces and ruled transition forms”have a clear the use, in practice, of surface forms that do not correspond to any geometric figure listed. Geometric forms and in particular ruled surfaces, respond to mathematical approaches that relate the placement of a line moving along two guidelines following a law. This law can be either a third given guideline, a plan in which all lines are parallel to (Catalan surfaces) or a fixed inclination (cone director). This article argues that this third law can be the equal distribution of the straight lines along both guidelines, so that each straight line divides the guideline into two parts in equal proportion [ES] Algunas figuras estudiadas en la tesis doctoral “Control gráfico de formas y superficies de transición” son superficies que no se corresponden con ninguna forma geométrica estándar. Este artículo argumenta que la forma de la arquitectura viene condicionada por las leyes de la construcción material y genera nuevas figuras tan geométricas como las clasificadas en los libros y teorías