MathDB
1996 AJHSME Problem 24

Source:

July 10, 2011
AMC

Problem Statement

The measure of angle ABCABC is 5050^\circ , AD\overline{AD} bisects angle BACBAC, and DC\overline{DC} bisects angle BCABCA. The measure of angle ADCADC is
[asy] pair A,B,C,D; A = (0,0); B = (9,10); C = (10,0); D = (6.66,3); dot(A); dot(B); dot(C); dot(D); draw(A--B--C--cycle); draw(A--D--C);
label("AA",A,SW); label("BB",B,N); label("CC",C,SE); label("DD",D,N); label("5050^\circ ",(9.4,8.8),SW); [/asy]
(A) 90(B) 100(C) 115(D) 122.5(E) 125\text{(A)}\ 90^\circ \qquad \text{(B)}\ 100^\circ \qquad \text{(C)}\ 115^\circ \qquad \text{(D)}\ 122.5^\circ \qquad \text{(E)}\ 125^\circ