MathDB
2022 Geo Div 2 P5

Source:

February 28, 2022
geometry

Problem Statement

Let ABCABC be an equilateral triangle of unit side length and suppose DD is a point on segment BC\overline{BC} such that DB<DC.DB<DC. Let MM and NN denote the midpoints of AB\overline{AB} and AC,\overline{AC}, respectively. Suppose XX and YY are the intersections of lines ABAB and ND,ND, and lines ACAC and MD,MD, respectively. Given that XY=4,XY=4, what is the value of DBDC?\frac{DB}{DC}?
Proposed by Kyle Lee