A treatise on special or elementary geometry (1877)
Olney, Edward, 1827-1887, Olney, Edward, 1827-1887. Elements of trigonometry, plane and spherical · New York : Sheldon · leaf 317
898. Theo.—The symmetrical of an angle,loith respect to a rectilinear axis of symmetry,is an equal angle. Sugs.—The student should be able to give the dem-onstration from the figure, in a manner altogethersimilar to the preceding ; or, drawing AB and AB, hecan base it upon the preceding. … ^,9.9. JProh.—Having given a poly-gon, to draw its symmetrical with respectto a given axis. Fig. 462. 900. Theo.—Any plane figure is^ equal to its symmetrical, with referenceto a rectilinear axis. Proof by applying one to the other by revo-lution. & OF SYMMETRY. 299 901k Def.—Two loci in space,…
Geometry · Trigonometry
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
