Smart, Edward Howard · London : Macmillian and Co. · leaf 64
s that formed by the bounding lines of an angle together withits internal and external bisectors. Let OB, OD be respectively the internal and externalbisectors of the angle AOC. (Fig. 13.) rpi AB AO AD . AB AD ihen — = — = —; .. —= . BO 00 CD BC DC Hence the range ABCD is harmonic, and by § 5 the… … Fig. 13. For (Fig. 13) if OA, OC be the conjugate pair at rightangles, we have as before, ECF being parallel to OA, EC = OF. HARMONIC FORMS 37 But OC is now at right angles to EF. .. the triangles OCE, OCF are congruent, and the angleBOD is bisected by OC. It must he carefully noted, however, that…
Geometry, Projective
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
