Question -
Answer -
Given : Sides BA and CA of тИЖABC are produced such that BA = AD are CA = AE. ED is joined.
To prove : DE || BC
Proof: In тИЖABC and тИЖDAE AB=AD (Given)
AC = AE (Given)
тИаBAC = тИаDAE (Vertically opposite angles)
тИ┤ тИЖABC тЙЕ тИЖDAE (SAS axiom)
тИ┤ тИаABC = тИаADE (c.p.c.t.)
But there are alternate angles
тИ┤ DE || BC