A cone has a circular base with a diameter of 18 inches. The height of the cone is 40 inches. What is the approximate lateral area of the cone? Use 3 point 1 4 for pi and round to the nearest whole number.

The radius is half the 18-inch diameter, so it is 9 inches. The slant height is √(40² + 9²) = √1,681 = 41 inches. Using the lateral area formula πrl gives 3.14 × 9 × 41 = 1,158.66, which rounds to 1,159 square inches, choice A.

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