In triangle ABC shown below, side AB is 10 and side AC is 8:

Triangle ABC with segment joining point D on segment AB and point E on segment AC.

Which statement is needed to prove that segment DE is parallel to segment BC and half its length?

Segment AD is 5, and segment AE is 4.
Segment AD is 4, and segment AE is 8.
Segment AD is 4, and segment AE is 5.
Segment AD is 5, and segment AE is 2.