14). (Take π value as 22/7)
circumference = 66in
2πr = 66in
2×22/7×r = 66
r = 66×7/2×22
r = 21/2in
d = 2r => d = 2×21/2
therefore diameter of the circle = 21in
15). (Take π value as 3.14)
Circumference = 3.14m
2πr = 3.14m
2×3.14×r = 3.14
r = 3.14/3.14×2
r = 1/2m
Therefore the radius of the circle = 0.5m
16). (Take π value as 22/7)
Circumference = 33km
2πr = 33km
2×22/7×r = 33
r = 33×7/2×22
r = 21/4
d = 2r
d = 2×21/4
d = 21/2km
Therefore the diameter of the circle = 10.5km
