Răspuns :
A=50
L=2l
...................
L=?
l=?
....................
A=L*l=>2l*l=50=>2l²=50 |÷2
l²=25⇒l=√25⇒l=5
L=2*5⇒L=10
Verificare: A=L*l=10*5=50
L=2l
...................
L=?
l=?
....................
A=L*l=>2l*l=50=>2l²=50 |÷2
l²=25⇒l=√25⇒l=5
L=2*5⇒L=10
Verificare: A=L*l=10*5=50