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All-Russian Olympiad
1980 All Soviet Union Mathematical Olympiad
298
298
Part of
1980 All Soviet Union Mathematical Olympiad
Problems
(1)
ASU 298 All Soviet Union MO 1980 angle wanted, equilateral starting
Source:
7/19/2019
Given equilateral triangle
A
B
C
ABC
A
BC
. Some line, parallel to
[
A
C
]
[AC]
[
A
C
]
crosses
[
A
B
]
[AB]
[
A
B
]
and
[
B
C
]
[BC]
[
BC
]
in
M
M
M
and
P
P
P
points respectively. Let
D
D
D
be the centre of
P
M
B
PMB
PMB
triangle,
E
E
E
be the midpoint of the
[
A
P
]
[AP]
[
A
P
]
segment. Find the angles of triangle
D
E
C
DEC
D
EC
.
geometry
Equilateral
angles