If △ABC≅△DEF, AB = DE and BC = EF, then the necessary condition for congruency is
∠A = ∠D
∠B = ∠E
∠C = ∠F
CA = DE
Answers
Step-by-step explanation:
(i) Consider the quadrilateral ABED
We have , AB=DE and AB∥DE
One pair of opposite sides are equal and parallel. Therefore
ABED is a parallelogram.
(ii) In quadrilateral BEFC , we have
BC=EF and BC∥EF. One pair of opposite sides are equal and parallel.therefore ,BEFC is a parallelogram.
(iii) AD=BE and AD∥BE ∣ As ABED is a ||gm ... (1)
and CF=BE and CF∥BE ∣ As BEFC is a ||gm ... (2)
From (1) and (2), it can be inferred
AD=CF and AD∥CF
(iv) AD=CF and AD∥CF
One pair of opposite sides are equal and parallel
⇒ ACFD is a parallelogram.
(v) Since ACFD is parallelogram.
AC=DF ∣ As Opposite sides of a|| gm ACFD
(vi) In triangles ABC and DEF, we have
AB=DE ∣ (opposite sides of ABED
BC=EF ∣ (Opposite sides of BEFC
and CA=FD ∣ Opposite. sides of ACFD
Using SSS criterion of congruence,
△ABC≅△DEF