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Question
The sum of the interior angles of a polygon is three times the sum of its exterior angles. Determine the number of sided of the polygon.
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Solution
\[\left\{ \left( 2n - 4 \right) \times 90° \right\} = 3 \times \left( \frac{360° }{n} \times n \right)\]
\[ \Rightarrow \left( n - 2 \right) \times 180 = 3 \times 360\]
\[ \Rightarrow n - 2 = 6\]
\[ \therefore n = 8\]
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