Question

in the. figure below ABCD and ABEF are parellograms prove CDFE is a parellogram

Answer 1

The parallelograms ABCD nd ABEF are on the same base BA nd b/w the same parallels CD nd EF..so ar.(parallelogramABCD)= ar.(parallelogramABEF )
Therefore corresponding sides must also be equal nd parallel i.e., CD=EF nd CD parallel to EF..so CDEF is a parallelogram..

Answer 2

from figure
AB||EF. (ABEF is a ||gm)

AB||DC. (ABCD is a ||gm)

so, EF||DC ------1
also
AB =EF &AB = DC ( same reason as above )

so, EF=DC -------2
from 1 &2
CDFE is a ||gm