MathDB
Area is less than half

Source: 2006 Korea National Olympiad #4

March 18, 2018
geometry

Problem Statement

On the circle O,O, six points A,B,C,D,E,FA,B,C,D,E,F are on the circle counterclockwise. BDBD is the diameter of the circle and it is perpendicular to CF.CF. Also, lines CF,BE,ADCF, BE, AD is concurrent. Let MM be the foot of altitude from BB to ACAC and let NN be the foot of altitude from DD to CE.CE. Prove that the area of △MNC\triangle MNC is less than half the area of □ACEF.\square ACEF.
Back to ProblemsView on AoPS