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1973 IMO Longlists
5
5
Part of
1973 IMO Longlists
Problems
(1)
Locus of all vertices A of all parallelograms ABCD
Source: IMO LongList 1973 - P5
6/6/2011
Given a ball
K
K
K
. Find the locus of the vertices
A
A
A
of all parallelograms
A
B
C
D
ABCD
A
BC
D
such that
A
C
≤
B
D
AC \leq BD
A
C
≤
B
D
, and the diagonal
B
D
BD
B
D
lies completely inside the ball
K
K
K
.
geometry
parallelogram
geometry unsolved