document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1149590>Question 1149590</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In the diagram to the bottom, ABCG is a parallelogram, and BF=21cm, FE=9cm. Find the length, in cm, of ED.\r<BR>\n" );
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document.write( "Diagram: https://imgur.com/a/ohBRyuL </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #770921 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13215)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=770921\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "(1) Triangles AFE and CFB are similar.  FE=9 and FB=21 are corresponding parts of those triangles, so the ratio of similarity is 9:21 or 3:7.<br><BR>\n" );
document.write( "(2) So let the lengths of corresponding parts AE and CB be 3x and 7x.<br><BR>\n" );
document.write( "(3) ABCG is a parallelogram; BC = 7x and AE = 3x.  Use that to find an expression for the length of EG.<br><BR>\n" );
document.write( "(4) Angles BAG and EGD are congruent because ABCG is a parallelogram.  Angles AEB and GED are congruent because they are vertical angles.<br><BR>\n" );
document.write( "(5) So triangles BAE and DGE are similar.  Sides AE and EG are corresponding parts of those triangles, giving you the ratio of similarity.<br><BR>\n" );
document.write( "(6) BE and ED are also corresponding parts of those triangles.  The length of ED is what you are to find; the length of BE is known from the given information.<br><BR>\n" );
document.write( "(7) Use the ratio of similarity of those two triangles to answer the question.<br><BR>\n" );
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