Step-by-step explanation:
The formula for arc length [for the angle in degrees] is:
here,
= degrees
= radius
using this we'll solve all the parts:
r = 10, n = 20:
from here, it is just simplification:
2 and 360 can be resolved: 360 divided by 2 = 180
10 and 180 can be resolved: 180 divided by 10 = 18
finally, both 20 and 18 are multiples of 2 and can be resolved:
Option (E)
r=3, n=6:
Option (D)
r=4 n=7
Option (C)
r=2 n=x
Option (D)
r=y n=x
Option (E)