The figure shows that OA is parallel to CB, and the arc leng

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[GMAT math practice question]

The figure shows that OA is parallel to CB, and the arc length AB is 8 cm, and ∠ AOB is 40. What is the arc length of BC?

Image

A. 20 cm
B. 22 cm
C. 24 cm
D. 26 cm
E. 28 cm
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by Max@Math Revolution » Thu Oct 31, 2019 12:02 am
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Since ∠AOB and ∠OBC are alternate interior angles, they are equal to each other, and we have ∠OBC = 40.

Image

∠BOA = 100 and the length of the arc BC is 8*(100/40) = 20.

Therefore, A is the answer.
Answer: A