Answer:
16
Step-by-step explanation:
DE is the vertical line x=1. It extends between y=2 and y=7, a distance of 5 units.
EF is the horizontal line y=7. It extends from x=1 to x=4, a distance of 3 units.
Then the perimeter of half the rectangle is 5+3 = 8 units.
The perimeter of the rectangle is 2·8 = 16 units.
