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Spain Mathematical Olympiad
1987 Spain Mathematical Olympiad
5
spanish angle chasing
spanish angle chasing
Source: Spanish Mathematical Olympiad 1987 P5
August 2, 2018
Angle Chasing
geometry
Problem Statement
In a triangle
A
B
C
,
D
ABC, D
A
BC
,
D
lies on
A
B
,
E
AB, E
A
B
,
E
lies on
A
C
AC
A
C
and
∠
A
B
E
=
3
0
o
,
∠
E
B
C
=
5
0
o
,
∠
A
C
D
=
2
0
o
\angle ABE = 30^o, \angle EBC = 50^o, \angle ACD = 20^o
∠
A
BE
=
3
0
o
,
∠
EBC
=
5
0
o
,
∠
A
C
D
=
2
0
o
,
∠
D
C
B
=
6
0
o
\angle DCB = 60^o
∠
D
CB
=
6
0
o
. Find
∠
E
D
C
\angle EDC
∠
E
D
C
.
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