document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1175260>Question 1175260</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If the equation (n-2)x180= sum of interior angles and when we are given the interior angles use this (n-2)x180=sum (n) but when given a sum of 900 have to use the original equation?  (n-2)x180=900  180n-360=900 180n=1260 n=7 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #800865 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=800865\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> yes.\r<BR>\n" );
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document.write( "the equation is that the sum of the internal angles is equal to (n - 2) * 180 where n is the number of sides in the polygon.\r<BR>\n" );
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document.write( "in a triangle, n = 3 and the sum of the internal angles is 1 * 180 = 180.\r<BR>\n" );
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document.write( "in a quadrilateral, n = 4 and the sum of the intenal angles is 2 * 180 = 360.\r<BR>\n" );
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document.write( "if the sum of the internal angles is 900, then the equation becomes:\r<BR>\n" );
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document.write( "(n - 2) * 180 = 900.\r<BR>\n" );
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document.write( "this simplifies to 180 * n - 360 = 900\r<BR>\n" );
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document.write( "add 360 to both sides of the equation to get 180 * n = 1260.\r<BR>\n" );
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document.write( "solve for n to get n = 7.\r<BR>\n" );
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document.write( "the polygon is a 7 sided figure.\r<BR>\n" );
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document.write( "i think that's called a heptagon.\r<BR>\n" );
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document.write( "here's more than you probably wanted to know about the names of polygons.\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF= \"https://www.mathsisfun.com/geometry/polygons.html\" target = \"_blank\">https://www.mathsisfun.com/geometry/polygons.html</a>\r<BR>\n" );
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document.write( " </SPAN>\n" );
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