1. A method of projecting a three dimensional figure to a two dimensional figure comprising: selecting a data set of three dimensional figures out of a stored data set of three dimensional figures, the data set of three dimensional figures being related to an associated dimensional line and other three dimensional figures; determining whether a data set of both ends of the dimensional line is associated with the three dimensional figure or the three dimensional figures, the three dimensional figure and figures being selected; obtaining two dimensional figures through performing a projection of the data set of three dimensional figures and the dimensional line onto a two dimensional plane on the case of the data set of both ends of dimensional line being associated with the three dimensional figures.