Răspuns :
P = 2(L+l)
850 = 2(L+l)
L = 5+l
850 = 2(5+l+l)
850 = 10+2l+2l
850 = 10+4l
4l = 850-10
4l = 840
l = 840:4
l = 210m
L = 5+210
L = 215m
850 = 2(L+l)
L = 5+l
850 = 2(5+l+l)
850 = 10+2l+2l
850 = 10+4l
4l = 850-10
4l = 840
l = 840:4
l = 210m
L = 5+210
L = 215m