Anthony, Gardner Chace, 1856- [from old catalog], Ashley, George Francis, [from old catalog] joint author · Boston, D. C. Heath & co. · leaf 62
. But ffJVis perpendicularto every line in the horizontal projecting planeof line A which intersects it, and, therefore,perpendicular to A\ Q.E.D. In like manner VN may be proved to beperpendicular to A . The converse of thisproposition is true. 63. To project a point on to an oblique… … Fig. 101
Geometry, Descriptive
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Brief synopsis of the course of lectures in descriptive geometry; as arranged for the first year Faculty of Applied Science and Engineering, University of Toronto. [By] J. Roy Cockburn (1922)](https://img.insideoutlibrary.com/img/200/ia-fybriefsynopsiso00cockuoft-12-7.webp)
