LET A,B,C BE AN ACUTE ANGLED TRIANGLE AND LET D,E,F BE FEET OF PERPENDICULARS FROM A,B,C RESPECTIVELY TO BC,CA,AB.LET THE PERPENDICULARS FROM F TO CB,CA,AD,BE MEET THEM IN P,Q,M,N RESPECTIVELY.PROVE THAT P,Q,M,N ARE COLLINEAR.3√
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