L+l= 1 370:2 =685 (m)
1/3 L-1/4 l=90 Folosim metoda figurativa
1/3L l_______l
1/4l l____l+90 ⇒ L=l+4×90 L=l+360
L l______________________l
l l_________________l +360 L+l=685m
Egalam L cu l
685-360=325
Aflam latimea: 325:2=162,5 m
Aflam lungimea 685-162,5=522,5 m
R. L=522,5 m l=162,5 m
Verificare: 2×522,5+2×162,5=1045+325=1370