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Defining regular polygons - class-IX
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If $R$ is the radius of circumscribing circle of a regular polygon of $n$ sides, then $R =?$
AnswerClick to flip back
A
$\dfrac{a}{2} cosec (\dfrac{\pi}{n})$
💡 Explanation:
since, it is a regular polygon so its interior angle will be equal
Hence, $nA=\pi\Rightarrow A=\dfrac{\pi}{n}$
and we know that
$\dfrac{a}{sinA}=2R\Rightarrow R=\dfrac{a}{2}cosec(\dfrac{\pi}{n})$
therefore,Answer is $C$