document.write( "Question 980769: in a triangle ABC, D and E are two points on sides AB and AC respectively so that DE parallel to BC and AD/DB=2/3.Then, the area of trapezium DECB/the area of triangle ABC is equal to ? \n" ); document.write( "

Algebra.Com's Answer #601859 by Edwin McCravy(20056) $\"\"$ $\"About$

You can put this solution on YOUR website!
in a triangle ABC, D and E are two points on sides AB and AC respectively so
\n" ); document.write( "that DE parallel to BC and AD/DB=2/3.Then, the area of trapezium DECB/the area
\n" ); document.write( "of triangle ABC is equal to ?
\n" ); document.write( "

\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "We will use three theorems and the fact that ΔADE∽ΔABC.     :\r\n" );
document.write( "\r\n" );
document.write( "(1).  If , then \r\n" );
document.write( "\r\n" );
document.write( "(2).  If , then \r\n" );
document.write( "\r\n" );
document.write( "(3).  In two similar triangles, the ratio of their areas is the square\r\n" );
document.write( " of the ratio of their sides.\r\n" );
document.write( "\r\n" );
document.write( "  given\r\n" );
document.write( "\r\n" );
document.write( " using (1)\r\n" );
document.write( "\r\n" );
document.write( " simplifying\r\n" );
document.write( "\r\n" );
document.write( " using (3)\r\n" );
document.write( "\r\n" );
document.write( " using (2)\r\n" );
document.write( "\r\n" );
document.write( ", simplifying\r\n" );
document.write( "\r\n" );
document.write( "Edwin

\n" ); document.write( "

\n" );