Smart, Edward Howard · London : Macmillian and Co. · leaf 231
straight lines. (Fig. 104a.) Let p, p be the given lines. Since for a cross-ratio we requirefour points, we can take any threepoints A, B, C on the line p tocoriespond respectively to anythree A, B, C on the line p. (h) To construct a pair of homo-graphic pencils at different ver-tices. (Fig.… … Fig. 104a. Then, if any point P be takenon the line p, the correspondingpoint P on p may be constructeduni(iuely by the method of § 7,Chap. II., as follows : On AA, the join of a pair ofcorresponding points, take anytwo points V, v. Let VB, VB intersect at BandVC, VC at C. Jcjin BC, cutting AA in…
Geometry, Projective
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
