Trigonometry : Pt. 2 : Algebraical Trigonometry / A. W. Siddons and R. T. Hughes. Algebra & trigonometry. Siddons, A. W. Hughes, R. T. jt. aut. Trigonometry Graphic methods. QA154.2 .A3124 2001 514 SIT 21 Includes index. Cambridge : University Press, c1940. c1940. 1940 Text v. : eng