MathDB
17th ibmo - el salvador 2002/q4.

Source: Spanish Communities

April 14, 2006
geometryangle bisector

Problem Statement

In a triangle ABC\triangle{ABC} with all its sides of different length, DD is on the side ACAC, such that BDBD is the angle bisector of ABC\sphericalangle{ABC}. Let EE and FF, respectively, be the feet of the perpendicular drawn from AA and CC to the line BDBD and let MM be the point on BCBC such that DMDM is perpendicular to BCBC. Show that EMD=DMF\sphericalangle{EMD}=\sphericalangle{DMF}.