- 191 -


cds = h , b d = a(c+s), P3(E) = P3 (F),

and
a+ s = a , b d = c(a +s), P3(E) = P3(G).
Thus P3 (E) = P3(F) = P (G), and 0F0' follows from 1(d). Hence ON= OM and the proof is complete.

A BIBLIOGRAPHY OF THE STEINER-LEHMUS THEOREM


CHARLES W. TRIGG, Professor Emeritus, Los Angeles City College

The following references to the Steiner-Lehmus Theorem and related theorems will serve to augment the bibliography given by Sauv6 in EUREKA (1976: 23-241.
1. The American Mathematical Monthly, 2 (1895), 157, 189-91; 3 (March 1896), 90; 5 (April 1898), 1o8; 9 (Feb. 1902), 43; 15 (Feb. 1908), 37; 24 (Jan. 1917), 33; 24 (Sept. 1917), 344; 25 (1918), 182-3; 40 (Aug. 1933), 1123.



5. Richard Philip Baker, The Problem of the Angle-Bisectors, University of Chicago Press, 98 pages (Circa 1911). O.P.
6. W.E. Bleick, "Angle Bisectors of an Isosceles Triangle," American Mathematical. Monthly, 55 (Oct. 1948), 495.
7. W.E. Buker, (Equal external bisectors), Solution of problem E305, American Mathematical Monthly, 45 (August 1938), 480.
8. Lu Chin-Shih, (Equal external bisectors), Solution of problem 1148, School Science and Mathematics, 31 (April 1931), 465-466.
9. Sister Mary Constantia, "Dr. Hopkins' proof of the angle bisector problem," The Mathematics Teacher, 57 (Dec. 1964), 539-541.
1o. J.J. Corliss, "If Two External Bisectors are Equal is the Triangle Isosceles?" School Science and Mathematics, 39 (Nov. 1939), 732-735.

12. A.W. Gillies, A.R. Pargetter, and H.G. Woyda, "Three notes inspired by the SteinerLehmus Theorem," Mathematical Gazette, 57 (Dec. 1973), 336-339.
13. William E. Heal, "Relating to the Demonstration of a Geometrical Theorem," American Mathematical Monthly, 25 (1918), 182-183.
14. Archibald Henderson, "The Lehmus-Steiner-Terquem Problem in Global Survey," Scripta Mathematica, 21 (1955), 223, 309.