Q : 11 In and , and . Vertices A, B and C are joined to vertices D, E and F respectively (see Fig. ). Show that quadrilateral ACFD is a parallelogram
To prove : quadrilateral ACFD is a parallelogram
Proof :
In ABED,
AD=BE.................1(ABED is a parallelogram)
AD||BE .................2(ABED is a parallelogram)
In BEFC,
BE=CF.................3(BEFC is a parallelogram)
BE||CF .................4(BEFC is a parallelogram)
From 2 and 4 , we get
AD||CF...........................5
From 1 and 3, we get
AD=CF...........................6
From 5 and 6, we get
AD||CF and AD=CF
Thus, quadrilateral ACFD is a parallelogram