Răspuns :
P = 2(L + l)
L = 3 * l
320 = 2(3 * l + l)
320 = 2 * 4 l
8 l = 320
l = 320 : 8
l = 40 cm
L = 3 * 40
l = 120 cm
L = 3 * l
320 = 2(3 * l + l)
320 = 2 * 4 l
8 l = 320
l = 320 : 8
l = 40 cm
L = 3 * 40
l = 120 cm
lungimea = 3x
latimea = x
( x +3x ) x2 = 320
4x = 320 :2
4x = 160
x = 160 : 4
x = 40
latimea = 40 cm
lungimea = 40 x 3 = 120 cm
latimea = x
( x +3x ) x2 = 320
4x = 320 :2
4x = 160
x = 160 : 4
x = 40
latimea = 40 cm
lungimea = 40 x 3 = 120 cm