document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=954475>Question 954475</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Dear Tutor,<BR>\n" );
document.write( "   So, I am in Geometry, and we are starting trig. The question is \"Points A,B,C, and D are consecutive vertices of a regular decagon with sides 20 cm long. Ray AB and Ray DC are drawn and intersect at X. Find BX\". I have drawn the problem out, and I get that it forms a 90 degree angle, but I can't figure out the rest. Please help me! And thank you for taking your time to help me!\r<BR>\n" );
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document.write( "-Shannon </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #582945 by </B><A HREF=/tutors/aboutme.mpl?userid=macston><B>macston(5194)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=macston><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=macston><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=582945\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> For a decagon (n=no. of sides=10)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28n-2%29%28180%29%29%2Fn ALIGN=MIDDLE  ALT=\"%28%28n-2%29%28180%29%29%2Fn\"   DISABLED_style= \"max-width:90%; height:auto;\" >=interior angle<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%288%29%28180%29%29%2F10 ALIGN=MIDDLE  ALT=\"%28%288%29%28180%29%29%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" >=144 degrees <BR>\n" );
document.write( "Interior and exterior angles are supplementary so exterior angles are 36 degrees. <BR>\n" );
document.write( "Angle XBD and Angle XCB are each 36 degrees, so Angle BXC is the third angle of the triangle =180-72=108 degrees <BR>\n" );
document.write( "From the midpoint of side BC to X is one leg of a right triangle, from midpoint to B is the other leg and BX is hypotenuse. Length of B to midpoint is (1/2)20cm=10cm so cos(36)=10cm/BX, BX=10cm/cos(36)=12.36cm <BR>\n" );
document.write( "ANSWER: BX=12.36 cm <BR>\n" );
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