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Reduce the radius of a circle with a circumference of 62.8 cm by 1 cm, and how many square centimeters will the area be reduced
62.8÷3.14÷2=10(cm)
3.14×（10×10-9×9）
=3.14×19
=59.66（cm2）
Reduce the radius of a circular piece of paper with a circumference of 62.8 cm by 1 cm, and how many square centimeters will the area be reduced?
Original radius: 62.8 △ 3.14 △ 2 = 10 (CM)
Current radius: 10-1 = 9 (CM)
Area reduction: 3.14 × 10 × 10-3.14 × 9 × 9 = 59.66 (square centimeter)
Reduce the radius of a circular piece of paper with a circumference of 62.8 cm by one centimeter, and how many square centimeters will the area be reduced?
62.8÷3.14÷2=10
10-1=9
10*10*3.14-9*9*3.14=59.66
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