Algebra.Com's Answer #833617 by ikleyn(52787)![\"\"](\"/images/stars/stars-13.gif\")  
You can put this solution on YOUR website!
.\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( " Step by step\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(1) The diagonal |BD| =  = 25 mm.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(2) From the area consideration, you have for the area of the triangle BCD\r\n" );
document.write( "\r\n" );
document.write( "  =  \r\n" );
document.write( "\r\n" );
document.write( " or\r\n" );
document.write( "\r\n" );
document.write( " 24*7 = 25*|FC|, which gives |FC| =  mm.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(3) Then from triangle CDF, |FD| =  = \r\n" );
document.write( "\r\n" );
document.write( " =  =  =  = 1.96 mm.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(4) Thus |FD| = |BE| = 1.96 mm.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(5) Hence, |EF| = 25 - 2*1.96 = 21.08 mm = 21  mm = 21  mm. ANSWER\r\n" );
document.write( " \r
\n" );
document.write( "\n" );
document.write( "Solved.\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "-----------------\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "It can be solved in different way, using similarity of triangles.\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "But in my solution, there are so many nice numbers on the way, that I decided to show you THIS version.\r
\n" );
document.write( "
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( " \n" );
document.write( " |