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Problems
Contests
International Contests
IMO Longlists
1986 IMO Longlists
65
65
Part of
1986 IMO Longlists
Problems
(1)
Prove that there is a point M on the circle C
Source:
8/29/2010
Let
A
1
A
2
A
3
A
4
A_1A_2A_3A_4
A
1
A
2
A
3
A
4
be a quadrilateral inscribed in a circle
C
C
C
. Show that there is a point
M
M
M
on
C
C
C
such that
M
A
1
−
M
A
2
+
M
A
3
−
M
A
4
=
0.
MA_1 -MA_2 +MA_3 -MA_4 = 0.
M
A
1
−
M
A
2
+
M
A
3
−
M
A
4
=
0.
geometry unsolved
geometry