Area = \\frac{1}{2} \\times \\text{base} \\times \\text{height}. Lower limits: base = 8 - 0.5 = 7.5 \\text{ cm}, height = 7 - 0.5 = 6.5 \\text{ cm}. Lower limit of area = \\frac{1}{2} \\times 7.5 \\times 6.5 = 24.375 \\text{ cm}^2, which rounds to 24.5 \\text{ cm}^2 (to 3 significant figures).