Use the image I added to see where I got the letters from.
Use the proper coordinates from each side to calculate each length:
A= -7-8
A=15
B=3-(-8)
B=11
C=2-8
C=6
D=-1-(-8)
D=7
E=-7-2
E=9
F=3-(-1)
F=4
Add all of these values together:
15+11+6+7+9+4=
46
So, the perimeter is 46 units.