Răspuns :
P = 2 × ( L + l )
10 m = 2 × ( l + 1 + l )
l + 1 + l = 10 : 2
l + 1 + l = 5 m
2l = 5 - 1
2l = 4 m
l = 4 : 2
l = 2 m
L = 2 + 1
L = 3 m
10 m = 2 × ( l + 1 + l )
l + 1 + l = 10 : 2
l + 1 + l = 5 m
2l = 5 - 1
2l = 4 m
l = 4 : 2
l = 2 m
L = 2 + 1
L = 3 m