So FB=2

< dec+<; FEB = & ltFe b+ & lt； BFE=90

So < bfe = <; Digital Equipment Corporation (digital equipment corporation)

So triangle BFE is similar to triangle DEC.

So BF/EC=BE/DC

That is 2/EC=(8-EC)/6.

The solution is EC=2.

So triangle BEF is equal to triangle DEC.

So DE=EF

When crossing f, make vertical lines FM and fn to BC, AD ad respectively.

AF/BF=FN/FM。

Again < EFD=90

With 1, it is easy to know that FN/FM=FD/FE.

once again