In ΔABC, we have AB = 5 cm, BC = 8 cm and CA = 7 cm. Since, D and E are the mid-points of AB and BC, respectively
In a ΔABC,D,E and F are respectively, the mid-points of BC, CA and AB. If the lengths of side AB, BC and CA are 7cm, 8cm and 9 cm, respectively, find the perimeter of ΔDEF.