University of Technology-IraqEngineering and Technology Journal1681-690027820090601On Projective 3-Space145514593570710.30684/etj.27.8.2ENMohammed S.KirdarAmal S.Al-MukhtarJournal Article20090601The purpose of this work is to give some definitions and prove some theorems on<br />projective 3-space S=PG(3,K) over a field K.<br />Also, the principle of duality in S is given which state that any theorem true in the<br />projective 3-space concerned with the points, planes and the incidence relation, the same<br />theorem is true by interchanging "point" and "plane" whenever they occur, where as the<br />dual of a line is a line.https://etj.uotechnology.edu.iq/article_35707_476f7f2547e56e07a4bb828d5f448fef.pdf