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9
2016-2017 Fall OMO Problem 9
2016-2017 Fall OMO Problem 9
Source:
November 16, 2016
Online Math Open
geometry
Problem Statement
In quadrilateral
A
B
C
D
ABCD
A
BC
D
,
A
B
=
7
,
B
C
=
24
,
C
D
=
15
,
D
A
=
20
,
AB=7, BC=24, CD=15, DA=20,
A
B
=
7
,
BC
=
24
,
C
D
=
15
,
D
A
=
20
,
and
A
C
=
25
AC=25
A
C
=
25
. Let segments
A
C
AC
A
C
and
B
D
BD
B
D
intersect at
E
E
E
. What is the length of
E
C
EC
EC
?Proposed by James Lin
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