Răspuns:
[tex]P=2(L+l)\\\\L=l+36\\\\312:2=l+36+l\\\\156-36=2l= > l=120:2= > l=60m-latimea\\\\L=60+36= > L=96m-lungimea\\\\96+6+6=108m-lungime.gard.viu\\\\60+6+6=72m-latime.gard.viu\\\\Pgard.viu=2*(108+72)=2*180=360m-lungimea. gadului.viu\\\\2*(72:12+1)=14-stalpi[/tex]