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Question
In the following figure, if ∠ABC = 20º, then ∠AOC is equal to ______.
Options
20º
40º
60º
10º
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Solution
In the following figure, if ∠ABC = 20º, then ∠AOC is equal to 40º.
Explanation:
Given: ∠ABC = 20°
By theorem “The angle subtended by an arc at the center of a circle is twice the angle subtended by it at remaining part of the circle”, we have:
∠AOC = 2 × ∠ABC
= 2 × 20°
= 40°
∴ ∠AOC = 40°
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