An elementary treatise on modern pure geometry (1893)
Lachlan, Robert · London, New York, Macmillan and Co. · leaf 63
be any pencil in involution, and ifa circle he drawn through the point 0 cutting the rays of the pencilin the points A, A, B, B,..., the chords AA, BB,... of this circlewill pass through a fixed point. … Let the circle cut the principal rays of the pencil in the pointsX, X, and let XX meet AA in the point K. THE PRINCIPAL RATS. 47 By § 84, we have KX : KX = XA . XA: XA . XA.But if R be the radius of the circle, Off- ^^ _ ^^ _^sin XOA sinXO^~ „ KX sin XOA . sin XOA 7i.i sin ZO^ . sin ZO^ = tan XOA .…
Geometry
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
