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1997 Tournament Of Towns
(539) 4
(539) 4
Part of
1997 Tournament Of Towns
Problems
(1)
angle between planes ABC' and ACD; tetrahedron tetrahedron inscribed in sphere
Source: TOT 539 1997 Spring S O4 - - Tournament Of Towns
9/11/2024
All edges of a tetrahedron
A
B
C
D
ABCD
A
BC
D
are equal. The tetrahedron
A
B
C
D
ABCD
A
BC
D
is inscribed in a sphere.
C
C
′
CC'
C
C
′
and
D
D
′
DD'
D
D
′
are diameters. Find the angle between the planes
A
B
C
ABC
A
BC
' and
A
C
D
′
ACD'
A
C
D
′
.(A Zaslavskiy)
geometry
3D geometry
tetrahedron
sphere
angles