Răspuns :
P=L+80
P=l+100
2L+2l=P
2L+2l=L+80=>L+2l=80|*(-2)
2L+2l=l+100=>2L+l=100
-2L-4l=-160
2L+l=100
-3l=-60=>l=20=>2L+20=100=>L=40
L=40
l=20
P=l+100
2L+2l=P
2L+2l=L+80=>L+2l=80|*(-2)
2L+2l=l+100=>2L+l=100
-2L-4l=-160
2L+l=100
-3l=-60=>l=20=>2L+20=100=>L=40
L=40
l=20
P = 2L + 80
P = 2 l +100
2 l = 80
l = 40 cm
L = 100 : 2
L = 50cm
P = 2 * 50 + 2 * 40
P = 180 cm
P = 2 l +100
2 l = 80
l = 40 cm
L = 100 : 2
L = 50cm
P = 2 * 50 + 2 * 40
P = 180 cm