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Albania Team Selection Test
2013 Albania Team Selection Test
4
4
Part of
2013 Albania Team Selection Test
Problems
(1)
Find the angle
Source: Albania IMO TST 2013
5/25/2013
It is given a triangle
A
B
C
ABC
A
BC
whose circumcenter is
O
O
O
and orthocenter
H
H
H
. If
A
O
=
A
H
AO=AH
A
O
=
A
H
find the angle
B
A
C
^
\hat{BAC}
B
A
C
^
of that triangle.
geometry
circumcircle
trigonometry
geometry proposed