MathDB
About the quadrilateral MNPQ

Source: IMO LongList 1982 - P45

September 10, 2010
symmetrygeometryIMO Longlistconvex quadrilateralIMO Shortlist

Problem Statement

Let ABCDABCD be a convex quadrilateral and draw regular triangles ABM,CDP,BCN,ADQABM, CDP, BCN, ADQ, the first two outward and the other two inward. Prove that MN=ACMN = AC. What can be said about the quadrilateral MNPQMNPQ?
Back to ProblemsView on AoPS