Răspuns :
P=2(L+l)=76
L=10+l => 2(10+l+l)=76
2(10+2l)=76
10+2l=76/2
10+2l=38
2l=38-10
2l=28
l=28/2
l=14 cm => L=10+l=10+28=38cm
L=10+l => 2(10+l+l)=76
2(10+2l)=76
10+2l=76/2
10+2l=38
2l=38-10
2l=28
l=28/2
l=14 cm => L=10+l=10+28=38cm