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Problems
Mathematics
Mathematics
Problem
Lines
A
B
AB
A
B
and
C
D
CD
C
D
intersect at
O
O
O
. Ray
O
E
OE
O
E
bisects
∠
A
O
C
\angle AOC
∠
A
O
C
, and ray
O
F
OF
O
F
bisects
∠
B
O
D
\angle BOD
∠
B
O
D
. Prove that
∠
A
O
E
=
∠
D
O
F
\angle AOE = \angle DOF
∠
A
O
E
=
∠
D
O
F
.
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