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About LinkBackslet in triangle ABC,AB=AC. D is the midpoint of BC.E is the foot of the perpendicular from D to AB,and F is the midpoint of DE.
Prove that AF is perpendicular to CE.
please help
This is a problem of USSR MO , i have solved it already .
Letbe the mid-pt of
, from
we have
.
Then consider thatso
because
is the mid-pt of
while
We can find thatis perpendicular to
.
( Median perpendicular to median as sides perpendicular to sides , check it ! )
Therefore ,is perpendicular to
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