Answer:
The length of the rhombus is =
Step-by-step explanation:
It is given that the Rhombus ADEF is inscribed into a triangle ABC so that they share angle A and the vertex E lies on the side BC.Then,
AE is the angle bisector of ∠A, so divides the sides of the triangle into a proportion:

⇒
⇒
Now, ΔDBE is similar to ΔABC, then
DE=
=
=
Thus, the length of the rhombus is =