Arc length = 2πr (a/360)
Where:
r= radius = 3 cm
a = central angle= 42°
We are going to calculate Arc length CB
Arc length = 2π 3(42/360) = 2.19 cm
Calculate the circumference :
C = π 2 r = π 2 (3) = 18.84
Subtract the arc length CB to the circumference
18.84-2.19 = 16.65 cm (option d)