Answer/Step-by-step explanation:
a. Circumference (C) = πd
d = 12 cm
π = 3.14
Exact value of C = π*12 = 12π cm
Approximate value of C = 12*3.14 = 37.68 cm
b. Circumference (C) = πd
d = 8 m
π = 3.14
Exact value of C = π*8 = 8π m
Approximate value of C = 8*3.14 = 25.12 m
c. Circumference (C) = πd
d = 6 km
π = 3.14
Exact value of C = π*6 = 6π km
Approximate value of C = 6*3.14 = 18.84 km
d. Circumference = πd
d = 9 ft
π = 22/7
Exact value of C = π*9 = 9π ft
Approximate value of C = 9*22/7 = 28.2857143 ≈ 28.29 ft (nearest hundredth)
e. Circumference = 2πr
r = 4 mm
π = 22/7
Exact value of C = 2*π*4 = 8π mm
Approximate value of C = 2*22/7*4 = 25.1428571 ≈ 25.14 mm (nearest hundredth)
f. Circumference = 2πr
r = 7 mi
π = 22/7
Exact value of C = 2*π*7 = 14π mi
Approximate value of C = 2*22/7*7 = 44 mi (nearest hundredth)