Răspuns :
Răspuns:
A(aria)= L•l
L•l=45m
L=4l
4l•l=45m
5l=45m
l=45÷5
l= 9m
L•l=45m
L•9=45m
L=45÷9
L=5
P(perimetrul)=2L+2l sau 2(L+l)
2•5+2•9= 10+18= 28
[tex]\it L\cdot\ell=45 \Rightarrow (\ell+4)\cdot\ell=45=9\cdot5 \Rightarrow L=9cm,\ \ell=5cm\\ \\ \mathcal{P} =2\cdot(L+\ell)=2\cdot(9+5)=2\cdot14=28\ cm[/tex]