Answer:
18 units
Step-by-step explanation:
Using the midpoint theorem, the perimeter of the triangle formed by joining the midpoints of the original triangle is exactly half the size in perimeter
What we mean in this case is that the perimeter of BAC IS two times the perimeter of EDF
perimeter of EDF is the sum of all the sides = 2 + 4 + 3 = 9
So the perimeter of BAC is 2 * 9 = 18