document.write( "Question 1166194: A polygon has two interior angles of 120° each and others are each 150°. Calculate
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Algebra.Com's Answer #790684 by ikleyn(52781)\"\" \"About 
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document.write( "Let the number of sides be \" n \" (same as the number of vertices).\r\n" );
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document.write( "Then we have for the sum of the interior angles 2*120° + (n-2)*150°.\r\n" );
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document.write( "From the other side, for each n-gon, the sum of its interior angles is (n-2)*180°.\r\n" );
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document.write( "Thus we have this equation\r\n" );
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document.write( "    2*120° + (n-2)*150° = (n-2)*180°.\r\n" );
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document.write( "Simplify it step by step and find n\r\n" );
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document.write( "    2*120 = (n-2)*180 - (n-2)*150\r\n" );
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document.write( "    240   = (n-2)*(180-150)\r\n" );
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document.write( "    240   = (n-2)*30\r\n" );
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document.write( "    n-2 = \"240%2F30\" = 8\r\n" );
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document.write( "    n                  = 8 + 2 = 10.\r\n" );
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document.write( "ANSWER.  n = 10.  The polygon is a decagon (10 sides and 10 vertices).\r\n" );
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