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A cylindrical wood with a diameter of 12cm and a height of 10cm on the bottom surface is sawed half along the diameter of the bottom surface to calculate the original surface area of the cylinder
Do you want the original surface area or the current one?
The diameter of the bottom surface of a cylinder is 10 cm. If the height is increased by 5 cm, the surface area will increase______ , volume increase______ ．
The radius of the bottom of the cylinder is: 10 △ 2 = 5 (CM), the increased surface area is: 3.14 × 10 × 5 = 157 (square cm); the increased volume is: 3.14 × 52 × 5 = 3.14 × 25 × 5 = 78.5 × 5 = 392.5 (cubic cm); a: the surface area will increase by 157 square cm, and the volume will increase by 392.5 cubic cm. So the answer is: 157 square cm, 392.5 cubic cm
The diameter of the bottom of the cylinder is 20cm and the height is 10cm
Be accurate!
The bottom radius is: 20 / 2 = 10 cm
The bottom area is: 3.14 * 10 * 10 = 314 square centimeters
The side area is: 3.14 * 20 * 10 = 628 square centimeters
The surface area is: 628 + 314 * 2 = 1256 square centimeters
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