Răspuns :
L=5l
Ppatrat=4l=4*54=216
Pdreptunghi=2l+2L=216
2l+2*5l=216
2l+10l=216
12l=216
l=18
L=90
Ppatrat=4l=4*54=216
Pdreptunghi=2l+2L=216
2l+2*5l=216
2l+10l=216
12l=216
l=18
L=90
L(lungimea)
l(latimea)
P(dreptunghi)=54*4
P(dreptunghi)=216 cm. l
l==> 2*l + 2*L =216
P(dreptunghi)=2*l + 2*L l L=5*l ==>2*l + 2*5*l=216 ==> 12*l =216 ==> l=216:12 ==> l=18
L=5*l ==> L=5*18 ==> L=90
l(latimea)
P(dreptunghi)=54*4
P(dreptunghi)=216 cm. l
l==> 2*l + 2*L =216
P(dreptunghi)=2*l + 2*L l L=5*l ==>2*l + 2*5*l=216 ==> 12*l =216 ==> l=216:12 ==> l=18
L=5*l ==> L=5*18 ==> L=90