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Greece Junior Math Olympiad
1986 Greece Junior Math Olympiad
3
3
Part of
1986 Greece Junior Math Olympiad
Problems
(1)
<ABD =<DBE=<EBC, <ACD=<DCE=<ECB - Greece Juniors 1986 p3
Source:
9/13/2024
Inside a triangle ABC, consider points
D
,
E
D, E
D
,
E
such that
∠
A
B
D
=
∠
D
B
E
=
∠
E
B
C
\angle ABD =\angle DBE=\angle EBC
∠
A
B
D
=
∠
D
BE
=
∠
EBC
and
∠
A
C
D
=
∠
D
C
E
=
∠
E
C
B
\angle ACD=\angle DC E=\angle ECB
∠
A
C
D
=
∠
D
CE
=
∠
ECB
. Calculate angles
∠
B
D
E
\angle BDE
∠
B
D
E
,
∠
B
E
C
\angle B EC
∠
BEC
,
∠
D
E
C
\angle D E C
∠
D
EC
in terms of the angle of the triangle
A
B
C
ABC
A
BC
.
geometry
angles