Question

In a triangle ABC, D is mid-point of BC; AD is produced up to E so that DE = AD. Prove that:

AB is parallel to EC.

Answer 1

Given: A ABC in which D is the midpoint of BC.
AD is produced to E so that DE=AD
We need to prove that

Also, DAB = DEC [ c.p.c t ]

AB || EC  [ DAB and DEC are alternate angels ]