Q : 11 In and , and . Vertices A, B and C are joined to vertices D, E and F respectively (see Fig. ). Show that
(ii) quadrilateral BEFC is a parallelogram
Given: In and , and .
To prove: quadrilateral BEFC is a parallelogram
Proof: In BEFC,
BC=EF (Given)
BC||EF (Given )
Hence, quadrilateral BEFC is a parallelogram.