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Prove that PE/PF=ME/NF - Iran NMO 2007 - Problem5

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September 22, 2010
geometrygeometry proposed

Problem Statement

Tow circles C,DC,D are exterior tangent to each other at point PP. Point AA is in the circle CC. We draw 22 tangents AM,ANAM,AN from AA to the circle DD (M,NM,N are the tangency points.). The second meet points of AM,ANAM,AN with CC are E,FE,F, respectively. Prove that PEPF=MENF\frac{PE}{PF}=\frac{ME}{NF}.