Let's calculate each of the requested values step-by-step:
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Circumference of a circle with a diameter of 4 feet: \[ C = \pi \times d \] Using \(\pi \approx 3.14\): \[ C = 3.14 \times 4 = 12.56 \text{ feet} \] The best estimate for the circumference is 13 feet.
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Circumference of a circle with a diameter of 3.25 meters: \[ C = \pi \times d \] Using \(\pi \approx 3.14\): \[ C = 3.14 \times 3.25 = 10.205 \text{ meters} \] Rounding to the hundredths place, the answer is 10.21 meters.
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Circumference of a circle with a radius of 2.5 feet: \[ C = 2 \times \pi \times r \] Using \(\pi \approx 3.14\): \[ C = 2 \times 3.14 \times 2.5 = 15.7 \text{ feet} \] The estimate rounded to the tenths place is 15.7 feet.
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Area of a circle with a radius of 12 feet: \[ A = \pi \times r^2 \] Using \(\pi \approx 3.14\): \[ A = 3.14 \times (12)^2 = 3.14 \times 144 = 452.16 \text{ square feet} \] The estimate rounded to the hundredths place is 452.16 square feet.
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Area of a circle with a diameter of 10 millimeters: First, find the radius: \[ r = \frac{d}{2} = \frac{10}{2} = 5 \text{ mm} \] Now compute the area: \[ A = \pi \times r^2 \] Using \(\pi \approx 3.14\): \[ A = 3.14 \times (5)^2 = 3.14 \times 25 = 78.5 \text{ square mm} \] The estimate rounded to the tenths place is 78.5 square mm.
To summarize:
- 13 feet
- 10.21 meters
- 15.7 feet
- 452.16 square feet
- 78.5 square mm