document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=974425>Question 974425</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the area of the triangle having verties at A(1,3,2) ,B(2,-1,1) ,C(-1,2,3). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #596419 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=596419\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the area of the triangle having vertices at A(1,3,2) ,B(2,-1,1) ,C(-1,2,3).<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "Vector AB = i - 4j - k<BR>\n" );
document.write( "Vector AC = -2i - j + k<BR>\n" );
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document.write( "The area is 1/2 the magnitude of the cross product.<BR>\n" );
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document.write( "+i +j +k<BR>\n" );
document.write( "+1 -4 -1<BR>\n" );
document.write( "-2 -1 +1<BR>\n" );
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document.write( "i*(-4-1) - j*(1-2) + k*(-1-8)<BR>\n" );
document.write( "= -5i + j - 9k<BR>\n" );
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document.write( "Mag = sqrt(5^2 + 1^1 + 9^2) = sqrt(107)<BR>\n" );
document.write( "Area = sqrt(107)/2 </SPAN>\n" );
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