MathDB
2016 LMT Individual #25

Source:

April 10, 2016

Problem Statement

Let ABCDABCD be a trapezoid with ABDCAB\parallel DC. Let MM be the midpoint of CDCD. If ADCD,ACBM,AD\perp CD, AC\perp BM, and BCBDBC\perp BD, find ABCD\frac{AB}{CD}.
Proposed by Nathan Ramesh