document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=115264>Question 115264</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me understand these<BR>\n" );
document.write( "in triangle ABC given that sides b=10,c=8, angle A=60degrees, find side a?\r<BR>\n" );
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document.write( "in triangle ABC given that sides a=4,b=8 and c=10, find cos B where B is the angle opposite to side b?\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #83841 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=83841\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Law of Cosines Formula:<BR>\n" );
document.write( "a^2 = b^2 + c^2 -2bc(Cos(A))<BR>\n" );
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document.write( "in triangle ABC given that sides b=10,c=8, angle A=60degrees, find side a?<BR>\n" );
document.write( "a^2 = 10^2 + 8^2 -2*10*8*Cos(60)<BR>\n" );
document.write( "a^2 = 164 -160*(1/2)<BR>\n" );
document.write( "a^2 = 84<BR>\n" );
document.write( "a = 2sqrt(21)<BR>\n" );
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document.write( "in triangle ABC given that sides a=4,b=8 and c=10, find cos B where B is the angle opposite to side b?<BR>\n" );
document.write( "Cos(B) = [a^2+c^2-b^2]/(2ac)<BR>\n" );
document.write( "Cos(B) = [16+100-64]/(2*4*10)<BR>\n" );
document.write( "Cos(B) = 52/80 = 13/20<BR>\n" );
document.write( "B = cos^-1(13/20)<BR>\n" );
document.write( "B = 49.46 degrees<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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