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Lusophon Mathematical Olympiad
2023 Lusophon Mathematical Olympiad
2
2
Part of
2023 Lusophon Mathematical Olympiad
Problems
(1)
Solve for the angle
Source: Lusophon Mathematical Olympiad 2023 Problem 2
5/27/2023
Let
D
D
D
be a point on the inside of triangle
A
B
C
ABC
A
BC
such that
A
D
=
C
D
AD=CD
A
D
=
C
D
,
∠
D
A
B
=
7
0
∘
\angle DAB=70^{\circ}
∠
D
A
B
=
7
0
∘
,
∠
D
B
A
=
3
0
∘
\angle DBA=30^{\circ}
∠
D
B
A
=
3
0
∘
and
∠
D
B
C
=
2
0
∘
\angle DBC=20^{\circ}
∠
D
BC
=
2
0
∘
. Find the measure of angle
∠
D
C
B
\angle DCB
∠
D
CB
.
geometry