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National Spain Olympiad 2004, Problem 2

Source: National Spain Olympiad 2004

May 30, 2017
geometryPlane Geometrymath olympiad

Problem Statement

ABCD{ABCD} is a quadrilateral, P{P} and Q{Q} are midpoints of the diagonals BD{BD} and AC{AC}, respectively. The lines parallel to the diagonals originating from P{P} and Q{Q} intersect in the point O{O}. If we join the four midpoints of the sides, X{X}, Y{Y}, Z{Z}, and T{T}, to O{O}, we form four quadrilaterals: OXBY{OXBY}, OYCZ{OYCZ}, OZDT{OZDT}, and OTAX{OTAX}. Prove that the four newly formed quadrilaterals have the same areas.