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Sweden Contests
Swedish Mathematical Competition
2017 Swedish Mathematical Competition
4
4
Part of
2017 Swedish Mathematical Competition
Problems
(1)
angle chasing, <AEC=45^o, altitude, angle bisector related
Source: 2017 (-18) Swedish Mathematical Competition p4
8/30/2020
Let
D
D
D
be the foot of the altitude towards
B
C
BC
BC
in the triangle
A
B
C
ABC
A
BC
. Let
E
E
E
be the intersection of
A
B
AB
A
B
with the bisector of angle
∠
C
\angle C
∠
C
. Assume that the angle
∠
A
E
C
=
4
5
o
\angle AEC = 45^o
∠
A
EC
=
4
5
o
. Determine the angle
∠
E
D
B
\angle EDB
∠
E
D
B
.
geometry
angle bisector
Angle Chasing
angles