P ABCD = 126 cm L = 2/6 * 126 => L = 1/3*126=> L = 126: 3 => L = 42 cm P ABCD = 2* L + 2 * l 126 = 2* 42 + 2 * l 2* l = 126 - 84 2 * l =42 => l = 42: 2 => l = 21 cm verifc: P ABCD = 126 cm 42 + 42 + 21 + 21 = 126 cm 84 + 42 = 126 cm 126 cm = 126 cm ( A)