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Mathematics
Mathematics
Problem
Lines
A
B
AB
A
B
and
C
D
CD
C
D
intersect at point
O
O
O
. Which angle is always equal to
∠
A
O
C
\angle AOC
∠
A
O
C
? a)
∠
B
O
A
\angle BOA
∠
B
O
A
b)
∠
B
O
C
\angle BOC
∠
B
O
C
c)
∠
B
O
D
\angle BOD
∠
B
O
D
d)
∠
A
O
D
\angle AOD
∠
A
O
D
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