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Poland - Second Round
1954 Poland - Second Round
5
5
Part of
1954 Poland - Second Round
Problems
(1)
orthogonal projection of quad is parallelogram
Source: Polish MO second round 1954 p5
8/29/2024
Given points
A
A
A
,
B
B
B
,
C
C
C
and
D
D
D
that do not lie in the same plane. Draw a plane through the point
A
A
A
such that the orthogonal projection of the quadrilateral
A
B
C
D
ABCD
A
BC
D
on this plane is a parallelogram.
geometry
3D geometry
projection
parallelogram