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 3.14 for π and round to the nearest whole number.

The radius is half the 18-inch diameter, so it is 9 inches. The cone’s slant height is √(9² + 40²) = √1,681 = 41 inches. Its lateral area is πrs, so 3.14 × 9 × 41 = 1,158.66, which rounds to 1,159 square inches. The correct choice is 1,159 square inches.

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