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Mathematics
Mathematics
Problem
Inside
△
A
B
C
\triangle ABC
△
A
B
C
, a point
D
D
D
is chosen such that
∠
A
D
C
=
∠
A
B
C
\angle ADC = \angle ABC
∠
A
D
C
=
∠
A
B
C
and
∠
A
C
D
=
∠
B
A
C
\angle ACD = \angle BAC
∠
A
C
D
=
∠
B
A
C
. Prove that
A
,
B
,
C
A, B, C
A
,
B
,
C
, and
D
D
D
lie on the same circle.
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