Răspuns :
P = 2*(L + l) = 276 - ( 2*128 + x) = 276 - 256 = 20/2 = 10
Lățimea = 10 m
Lățimea = 10 m
P=2×L+2×l
276=2×128+2×l
276=256+2×l
2×l=276-256
2×l=20
l=20/2
l=10
276=2×128+2×l
276=256+2×l
2×l=276-256
2×l=20
l=20/2
l=10