Measured area = 5^2 = 25 \\text{ cm}^2. Upper limit = 5.5^2 = 30.25 \\text{ cm}^2, lower limit = 4.5^2 = 20.25 \\text{ cm}^2. Maximum absolute error = \\max(30.25 - 25, 25 - 20.25) = 5.25 \\text{ cm}^2, which is 5.5 \\text{ cm}^2 (to 2 significant figures).