Answer/Step-by-step explanation:
Recall: circumference of a circle, C = πd or C = 2πr
Where d = diameter
Radius (r) = ½ of diameter
1. Radius (r) = 3 cm
Diameter (d) = 2(3) = 6 cm
Circumference = πd = π*6
C = 18.8495559 ≈ 18.8 cm (nearest tenth)
2. Radius (r) = 6 in.
Diameter (d) = 2(6) = 12 in.
Circumference = πd = π*12
C = 37.6991118 ≈ 37.7 in. (nearest tenth)
3. Radius (r) = 9 mm
Diameter (d) = 2(9) = 18 mm
Circumference = πd = π*18
C = 56.5486678 ≈ 56.5 mm (nearest tenth)
4. Radius (r) = ½(4.8) = 2.4 cm
Diameter (d) = 4.8 cm
Circumference = πd = π*4.8
C = 15.0796447 ≈ 15.1 cm (nearest tenth)
5. Radius (r) = ½(7) = 3.5 cm
Diameter (d) = 7 cm
Circumference = πd = π*7
C = 21.9911486 ≈ 22.0 cm (nearest tenth)
6. Radius (r) = ½(14) = 7 cm
Diameter (d) = 14 cm
Circumference = πd = π*14
C = 43.9822972 ≈ 44.0 cm (nearest tenth)