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CMIMC Problems
2021 CMIMC
9
9
Part of
2021 CMIMC
Problems
(1)
2021 Team P9
Source:
3/2/2021
Let
A
B
C
ABC
A
BC
be a triangle with circumcenter
O
O
O
. Additionally,
∠
B
A
C
=
2
0
∘
\angle BAC=20^\circ
∠
B
A
C
=
2
0
∘
and
∠
B
C
A
=
7
0
∘
\angle BCA = 70^\circ
∠
BC
A
=
7
0
∘
. Let
D
,
E
D, E
D
,
E
be points on side
A
C
AC
A
C
such that
B
O
BO
BO
bisects
∠
A
B
D
\angle ABD
∠
A
B
D
and
B
E
BE
BE
bisects
∠
C
B
D
\angle CBD
∠
CB
D
. If
P
P
P
and
Q
Q
Q
are points on line
B
C
BC
BC
such that
D
P
DP
D
P
and
E
Q
EQ
EQ
are perpendicular to
A
C
AC
A
C
, what is
∠
P
A
Q
\angle PAQ
∠
P
A
Q
?Proposed by Daniel Li
geometry