MathDB
2016 preRMO p5, line perpendicular to BC bisects triangle's area

Source:

August 9, 2019
geometryareas

Problem Statement

Consider a triangle ABCABC with AB=13,BC=14,CA=15AB = 13, BC = 14, CA = 15. A line perpendicular to BCBC divides the interior of BC\vartriangle BC into two regions of equal area. Suppose that the aforesaid perpendicular cuts BCBC at DD, and cuts ABC\vartriangle ABC again at EE. If LL is the length of the line segment DEDE, find L2L^2.