MathDB
right isosceles wanted, square, rhombus (2014 Romanian NMO grade VII P2)

Source:

May 28, 2020
geometryrhombussquareperpendicularisoscelesright triangle

Problem Statement

Outside the square ABCDABCD, the rhombus BCMNBCMN is constructed with angle BCMBCM obtuse . Let PP be the intersection point of the lines BMBM and ANAN . Prove that DM⊥CPDM \perp CP and the triangle DPMDPM is right isosceles .
Back to ProblemsView on AoPS