document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1179702>Question 1179702</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Regular octagon ABCDEFGH has a side length of<BR>\n" );
document.write( "2cm. Find the area of square ACEG </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #809336 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=809336\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "let the side of square be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a ALIGN=MIDDLE  ALT=\"a\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "the area <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=a%5E2 ALIGN=MIDDLE  ALT=\"A=a%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "since <<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+ABC ALIGN=MIDDLE  ALT=\"+ABC\"   DISABLED_style= \"max-width:90%; height:auto;\" > (interior angle of the octagon) is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=135 ALIGN=MIDDLE  ALT=\"135\"   DISABLED_style= \"max-width:90%; height:auto;\" >°, we can use cosine formula to calculate <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a ALIGN=MIDDLE  ALT=\"a\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2=2%5E2%2B2%5E2-2%2A2%2A2%2Acos%28135%29 ALIGN=MIDDLE  ALT=\"a%5E2=2%5E2%2B2%5E2-2%2A2%2A2%2Acos%28135%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2=8-8%2Acos%28135%29 ALIGN=MIDDLE  ALT=\"a%5E2=8-8%2Acos%28135%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >....write <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28135%29 ALIGN=MIDDLE  ALT=\"cos%28135%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > as a <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28180-45%29=cos%28-45%29=-cos%2845%29 ALIGN=MIDDLE  ALT=\"cos%28180-45%29=cos%28-45%29=-cos%2845%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2=8-8%2A%28-cos%2845%29%29 ALIGN=MIDDLE  ALT=\"a%5E2=8-8%2A%28-cos%2845%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >............<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-cos%2845%29=-sqrt%282%29%2F2 ALIGN=MIDDLE  ALT=\"-cos%2845%29=-sqrt%282%29%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2=8-8%2A%28-sqrt%282%29%2F2%29 ALIGN=MIDDLE  ALT=\"a%5E2=8-8%2A%28-sqrt%282%29%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2=8%2B4sqrt%282%29 ALIGN=MIDDLE  ALT=\"a%5E2=8%2B4sqrt%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5E2=13.7 ALIGN=MIDDLE  ALT=\"a%5E2=13.7\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "=> the area <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=13.7cm%5E2 ALIGN=MIDDLE  ALT=\"A=13.7cm%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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