document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=765504>Question 765504</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two parallel chords on opposite sides of the centre of a circle are 9 cm apart. If the chords are 8 cm and 12 cm long, then what is the radius of the circle? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #466212 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=466212\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Two parallel chords on opposite sides of the centre of a circle are 9 cm apart. If the chords are 8 cm and 12 cm long, then what is the radius of the circle?<BR>\n" );
document.write( "***<BR>\n" );
document.write( "I don't have the means to draw the sketch, but I can try to describe it to you. I am working with two right triangles. Both triangles have the radius as the hypotenuse with a known leg=1/2 of the length of the respective chords (4 and 6 cm). The sum of the unknown legs=distance(9cm) between the given chords.<BR>\n" );
document.write( "r=radius<BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28r%5E2-4%5E2%29%2Bsqrt%28r%5E2-6%5E2%29=9 ALIGN=MIDDLE  ALT=\"sqrt%28r%5E2-4%5E2%29%2Bsqrt%28r%5E2-6%5E2%29=9\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28r%5E2-4%5E2%29=9-sqrt%28r%5E2-6%5E2%29 ALIGN=MIDDLE  ALT=\"sqrt%28r%5E2-4%5E2%29=9-sqrt%28r%5E2-6%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "square both sides<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2-16=81-18%2Asqrt%28r%5E2-36%29%2Br%5E2-36 ALIGN=MIDDLE  ALT=\"r%5E2-16=81-18%2Asqrt%28r%5E2-36%29%2Br%5E2-36\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=18%2Asqrt%28r%5E2-36%29=61 ALIGN=MIDDLE  ALT=\"18%2Asqrt%28r%5E2-36%29=61\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28r%5E2-36%29=61%2F18 ALIGN=MIDDLE  ALT=\"sqrt%28r%5E2-36%29=61%2F18\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "square both sides again<BR>\n" );
document.write( "r^2-36=11.48<BR>\n" );
document.write( "r^2=36+11.48=47.48<BR>\n" );
document.write( "r=&#8730;47.48<BR>\n" );
document.write( "r=6.89 cm </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );