Kenison, Ervin, Bradley, Harry Cyrus, 1871-1936 · New York : The Macmillan Company · leaf 47
a ray is shown by the line L,Fig. 55. 40. Shadow of a Point. The shadow on V of the point a,Fig. 55, is the point, aa in which the ray of light, L, passing through a, intersects V. The shadowon H is the point, as, where L pierces H.It will be noted that the points atand as are the traces (§ 37) of… … Fig. 55. 41. Opaque and Transparent Planes.In order that an actual shadow maybe cast, it is necessary that the planereceiving the shadow be opaque. Thus, in Fig. 55, if V be con-sidered opaque, at is the actual shadow of the point a; but ifV be considered transparent and H opaque, as will be…
Geometry, Descriptive
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
