5. D, E and F are respectively the mid-points of the sides BC, CA and AB of a ΔABC. Show that (i) BDEF is a parallelogram. (ii) ar(DEF) = ¼ ar(ABC) (iii) ar (BDEF) = ½ ar(ABC) 5. D CA and AB of a ΔABC. Show that (i) BDEF is a parallelogram. (ii) ar(DEF) = [...]