what is the sum of the measures of the interior angles of a 27-gon

Each interior angle is 180° - 360°/27  so 27 of them gives:  27*180° - 360° = 4500°

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Remember the formula is (n-2)*180

 

So to find the sum of the angles of a 27-gon, substitute 27 for n and follow through the formula.

 

27-2=25 

 

25*180 = 4500