document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=233725>Question 233725</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The measure of an interior angle of a regular polygon is 120. What is the number of sides for that polygon? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #172473 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=172473\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The sum of the interior angles of a polygon is equal to:\r<BR>\n" );
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document.write( "(n-2) * 180\r<BR>\n" );
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document.write( "Each interior angle is equal to:\r<BR>\n" );
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document.write( "((n-2) * 180) / n\r<BR>\n" );
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document.write( "That means that:\r<BR>\n" );
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document.write( "120 = (n-2) * 180) / n\r<BR>\n" );
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document.write( "Multiply both sides by n to get:\r<BR>\n" );
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document.write( "120 * n = (n-2) * 180\r<BR>\n" );
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document.write( "Remove parentheses to get:\r<BR>\n" );
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document.write( "120 * n = 180 * n - 360\r<BR>\n" );
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document.write( "Subtract 120 * n from both sides and add 360 to both sides to get:\r<BR>\n" );
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document.write( "360 = 180 * n - 120 * n\r<BR>\n" );
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document.write( "Combine like terms to getr:\r<BR>\n" );
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document.write( "360 = 60 * n\r<BR>\n" );
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document.write( "Divide both sides by 60 to get:\r<BR>\n" );
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document.write( "6 = n\r<BR>\n" );
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document.write( "Number of sides of the polygon is 6 which makes it a hexagon.\r<BR>\n" );
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document.write( "Total degrees in a hexagon is (6-2) = 4 * 180 = 720\r<BR>\n" );
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document.write( "720 / 6 = 120 equals degree of each angle.\r<BR>\n" );
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document.write( "To colnfirm the formula is correct, take a polygon you know, like a triangle.\r<BR>\n" );
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document.write( "Each angle = 60\r<BR>\n" );
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document.write( "60 = (n-2) * 180 / n\r<BR>\n" );
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document.write( "60 * n = 180 * n - 360\r<BR>\n" );
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document.write( "120*n = 360\r<BR>\n" );
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document.write( "n = 3\r<BR>\n" );
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document.write( "formula is confirmed as correct.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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