document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=474554>Question 474554</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the approximate measure of angle C in a triangle with a = 21, b = 14, and c = 28?<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #325496 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=325496\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> first let's use law of cosines\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos+C+=+%28+21%5E2+%2B+14%5E2+-+28%5E2+%29+%2F+%282+%2A+21+%2A+14%29 ALIGN=MIDDLE  ALT=\"cos+C+=+%28+21%5E2+%2B+14%5E2+-+28%5E2+%29+%2F+%282+%2A+21+%2A+14%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos+C+=+%28+441+%2B+196+-+784+%29+%2F+588 ALIGN=MIDDLE  ALT=\"cos+C+=+%28+441+%2B+196+-+784+%29+%2F+588\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos+C+=++-147%2F588 ALIGN=MIDDLE  ALT=\"cos+C+=++-147%2F588\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos+C+=++-0.25 ALIGN=MIDDLE  ALT=\"cos+C+=++-0.25\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "The inverse function of cosine.\r<BR>\n" );
document.write( "\n" );
document.write( "Basic idea: To find cos-1 (-0.25), we ask \"what angle has cosine equal to -0.25?\" \r<BR>\n" );
document.write( "\n" );
document.write( "The answer is:\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=C+=+104.5 ALIGN=MIDDLE  ALT=\"C+=+104.5\"   DISABLED_style= \"max-width:90%; height:auto;\" > °\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );