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International Contests
IMO Longlists
1990 IMO Longlists
91
91
Part of
1990 IMO Longlists
Problems
(1)
Prove that OM = OK - ILL 1990 TUR2
Source:
9/19/2010
Quadrilateral
A
B
C
D
ABCD
A
BC
D
has an inscribed circle with center
O
O
O
. Knowing that
A
B
=
C
D
AB = CD
A
B
=
C
D
, and
M
,
K
M, K
M
,
K
are the midpoints of
B
C
,
A
D
BC, AD
BC
,
A
D
respectively. Prove that
O
M
=
O
K
.
OM = OK.
OM
=
O
K
.
geometry unsolved
geometry