Răspuns :
200 = 2 ( L + l )
L = 4 l => 200 = 2 ( 4l + l )
200 = 2 · 5l
200 = 10l /10
l = 20 cm => L = 4 · 20 => L = 80 cm .
L = 4 l => 200 = 2 ( 4l + l )
200 = 2 · 5l
200 = 10l /10
l = 20 cm => L = 4 · 20 => L = 80 cm .