document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=983093>Question 983093</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The interior angles of a polygon are in A.P. if the smallest angle is 120° and common difference is 5° then the number of sides in polygon is ? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #603928 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=603928\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> first term: 120<BR>\n" );
document.write( "second term: 120+5<BR>\n" );
document.write( "third term: 120+5*2<BR>\n" );
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document.write( "nth term: 120+5*(n-1)<BR>\n" );
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document.write( "Sum of the arithmetic terms\r<BR>\n" );
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document.write( "Sn = n*(a1 + an)/2\r<BR>\n" );
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document.write( "Sn = n*(120 + 120+5*(n-1))/2\r<BR>\n" );
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document.write( "Sn = n*(120 + 120+5n-5)/2\r<BR>\n" );
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document.write( "Sn = n*(5n+235)/2\r<BR>\n" );
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document.write( "Sum of angles in a polygon\r<BR>\n" );
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document.write( "S = 180(n-2)\r<BR>\n" );
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document.write( "n*(5n+235)/2 = 180(n-2) ... replace S with the arithmetic sum found above\r<BR>\n" );
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document.write( "n*(5n+235) = 2*180(n-2)\r<BR>\n" );
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document.write( "5n^2+235n = 360n-720\r<BR>\n" );
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document.write( "5n^2+235n - 360n+720 = 0\r<BR>\n" );
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document.write( "5n^2-125n+720 = 0\r<BR>\n" );
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document.write( "Now use the quadratic formula to solve for n. I'll let you do this part.\r<BR>\n" );
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document.write( "If you get any n values that are negative or not whole numbers, then ignore them. The value of n is going to be some positive whole number.  </SPAN>\n" );
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