Answer with explanation:
Given : In ΔABC,
Length of side AC= 4 cm
Length of side AB= 8 cm
To Prove:

Proof:
The theorem of geometry ,which is needed to prove that in ΔABC, BC=2 DE, is →→→→Line Segment Joining the mid point of two sides of triangle is parallel to third side and is half of it.
So, If D and E are mid point of AB and AC,then
→→DE║BC,and,

So,→ , AD= 4 cm and A E= 2 cm