document.write( "Question 1158275: Work out the size of an exterior and an interior angle of a regular 18-sided polygon.\r
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Algebra.Com's Answer #781184 by math_helper(2461)![]() ![]() You can put this solution on YOUR website! Total sum of interior angles = 180*(number of sides - 2) (think about how many triangles you can draw, each has 180 degrees). \r \n" ); document.write( "\n" ); document.write( "180(18-2) = 2880 \r \n" ); document.write( "\n" ); document.write( "2880/18 = \r \n" ); document.write( "\n" ); document.write( "Each exterior angle is the supplement to the interior angle: 180-160 = \n" ); document.write( "[ Also note: there are 360 degrees around the 18-gon, so another way to find the exterior angle is to divide 360 by the number of sides: 360/18 = 20 ] \n" ); document.write( " \n" ); document.write( " |