MathDB
BMT 2020 Fall - Geometry 8

Source:

December 30, 2021
geometry

Problem Statement

Let triangle ABC \vartriangle ABC have AB=17AB = 17, BC=14BC = 14, CA=12CA = 12. Let MAM_A, MBM_B, MCM_C be midpoints of BC\overline{BC}, AC\overline{AC}, and AB\overline{AB} respectively. Let the angle bisectors of A A, B B, and CC intersect BC\overline{BC}, AC\overline{AC}, and AB\overline{AB} at PP, QQ, and RR, respectively. Reflect MAM_A about AP\overline{AP}, MBM_B about BQ\overline{BQ}, and MCM_C about CR\overline{CR} to obtain MAM'_A, MBM'_B, MCM'_C, respectively. The lines AMAAM'_A, BMBBM'_B, and CMCCM'_C will then intersect BC\overline{BC}, AC\overline{AC}, and AB\overline{AB} at DD, EE, and FF, respectively. Given that AD\overline{AD}, BE\overline{BE}, and CF\overline{CF} concur at a point KK inside the triangle, in simplest form, the ratio [KAB]:[KBC]:[KCA][KAB] : [KBC] : [KCA] can be written in the form p:q:rp : q : r, where pp, qq and r r are relatively prime positive integers and [XYZ][XYZ] denotes the area of XYZ\vartriangle XYZ. Compute p+q+rp + q + r.