In a △ABC, D, E and F are te mid-points of side Bc, CA and AB respectively, If BC = 14.4 cm, CA = 15.2 cm and AB = 12.4 cm, what is the perimeter (in cm) of the △DEF?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 21
In ΔABC, D, E, and F are the midpoints of sides AB, BC, and AC respectively. Since in ΔABC, F is the midpoint of AC and D is the midpoint of AB.
By Midpoint theorem -
DE = AC/2 = 15.2/2 = 7.6
EF = AB/2 = 12.4/2 = 6.2
DF = BC/2 = 14.4/2 = 7.2
Perimeter = DE + EF + BC = 7.6 + 6.2 + 7.2 = 21