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Problem
Problem
In a scalene acute
Δ
A
B
C
\Delta ABC
Δ
A
B
C
, it is known that line joining circumcentre and orthocentre is parallel to
B
C
BC
B
C
. Prove that the angle
A
∈
(
π
3
,
π
2
)
A \in \left( \frac{\pi}{3}, \frac{\pi}{2} \right)
A
∈
(
3
π
,
2
π
)
.
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