document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=512940>Question 512940</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the area of the triangle whose vertices have coordinates (-8,3), (-8,-4), and (6,3). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #342799 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=342799\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the area of the triangle whose vertices have coordinates (-8,3), (-8,-4), and (6,3).<BR>\n" );
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document.write( "Label A(-8,3), B(-8,-4), and C(6,3).<BR>\n" );
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document.write( "A & B have the same x value, call AB the base, length = 7<BR>\n" );
document.write( "A & C have the same y value, so it's a right triangle, height = 14<BR>\n" );
document.write( "Area = b*h/2 = 49 sq units.<BR>\n" );
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document.write( "A general method:<BR>\n" );
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document.write( "A..  B..  C..  A<BR>\n" );
document.write( "-8 -8 +6 -8<BR>\n" );
document.write( "+3 -4 +3 +3<BR>\n" );
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document.write( "Add the diagonal products starting upper left<BR>\n" );
document.write( "-8*-4 + -8*3 + 6*3 = 32 - 24 + 18 = 26<BR>\n" );
document.write( "Add the diagonal products starting lower left<BR>\n" );
document.write( "3*-8 + -4*6 + 3*-8 = -24 - 24 - 24 = -72<BR>\n" );
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document.write( "The difference is 98.<BR>\n" );
document.write( "The area is 1/2 that, = 49 sq units.<BR>\n" );
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document.write( "Same answer, but the 2nd method works for ANY polygon, ANY # of sides. </SPAN>\n" );
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