Question

Find length DE.

Answer 1

Attachment here

Answer 2

You are dealing with similar triangles.

Answer 3

When you have similar triangles, corresponding sides have proportional lengths.

Answer 4

Im having trouble understanding that/

Answer 5

Let me show you a simpler example.

Answer 6

This is not your problem. This is just an example fro me to explain similar triangles to you.

Answer 7

ok

Answer 8

The two right triangles above are similar triangles.
Do you notice that every side of the right triangles is twice as long as the corresponding side of the left triangle?