Answer :
just add 3 to each dimention twice for each side
12+3+3=18
15+3+3=21
perimiter=2(L+W)
P=2(21+18)
P=2(39)
P=78
aswer is 78ft
see attachmetn for help
12+3+3=18
15+3+3=21
perimiter=2(L+W)
P=2(21+18)
P=2(39)
P=78
aswer is 78ft
see attachmetn for help
