Răspuns :
L=lungimea; l= latimea si P = perimetru
L =8+l
P =2(L+l)
56=2(8+l+l )
8+2l = 56:2
8+2l=28
2l=28-8
2l=20
l=20:2
l=10 m
L=8+10
L =18 m
VERFICARE : 56 =2( 10+18)
56=2*28
56=56
L =8+l
P =2(L+l)
56=2(8+l+l )
8+2l = 56:2
8+2l=28
2l=28-8
2l=20
l=20:2
l=10 m
L=8+10
L =18 m
VERFICARE : 56 =2( 10+18)
56=2*28
56=56