L=l+8
A=L*l
560=(l+8)*l
l² +8l -560=0
l² +8l +16 -576=0
(l+4)² -576=0
[(l+4)+24][(l+4)-24]=0
(l+28)(l-20)=0
l+28=0 ∧ l-20=0
l= -28∉ N l=20
L=20+8
L=28
b) P patrat= 4*8√2= 32√2
Pdreptunghi=32√2
2L+2l=32√2 |:2
L+l=16√2
l+8+l=16√2
l= (16√2-8)/2
l= 4√2 -4
L=4√2 -4+8
L=4√2 +4
