MathDB
Math Prize 2021 Problem 8

Source:

September 19, 2021
Math Prize for Girls

Problem Statement

In ABC\triangle ABC, let point DD be on BC\overline{BC} such that the perimeters of ADB\triangle ADB and ADC\triangle ADC are equal. Let point EE be on AC\overline{AC} such that the perimeters of BEA\triangle BEA and BEC\triangle BEC are equal. Let point FF be the intersection of AB\overline{AB} with the line that passes through CC and the intersection of AD\overline{AD} and BE\overline{BE}. Given that BD=10BD = 10, CD=2CD = 2, and BF/FA=3BF/FA = 3, what is the perimeter of ABC\triangle ABC?