In given figure, If ∠ADE=∠CBA show that △ADE∼△ABC If AD=3 8cm,AE=3 6cm,BE=2 1cm and BC=4 2cm, find

In given figure, If ∠ADE=∠CBA show that △ADE∼△ABC. If AD=3.8cm,AE=3.6cm,BE=2.1cm and BC=4.2cm, find DE.