document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=414390>Question 414390</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the area of polygon ABCD if the coordinates of the vertices are A(5,-1), B(9,2), C(9,9), and D(0,5). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #290657 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=290657\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Find the area of polygon ABCD if the coordinates of the vertices are A(5,-1), B(9,2), C(9,9), and D(0,5).<BR>\n" );
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document.write( "A - B - C- D-A<BR>\n" );
document.write( "+5 +9 +9 +0 +5<BR>\n" );
document.write( "-1 +2 +9 +5 -1<BR>\n" );
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document.write( "Add diagonals from upper left<BR>\n" );
document.write( "5*2 + 9*9 + 9*5 = 10 + 81 + 45 = 136<BR>\n" );
document.write( "Add diagonals from lower left<BR>\n" );
document.write( "-1*9 + 2*9 + 9*0 + 5*5 = -9 + 18 + 25 = 34<BR>\n" );
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document.write( "Difference = 102<BR>\n" );
document.write( "Area = 102/2 = 51 sq units<BR>\n" );
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document.write( "PS  It works for any # of points.<BR>\n" );
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