You can put this solution on YOUR website! Find the sum of the interior angles of a polygon with 39 sides.
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Sum of the EXTERIOR angles is 360.
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Each exterior angle is 360/39 = 9.2308 degrees
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Therefore, each interior angle is 180-9.2308 = 170.7692 degrees
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So the sum of the interior angles is 39*170.7592 = 6660 degrees
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Cheers,
Stan H.