Answer:
The missing variable r = 3
Explanation:
C = 2πr
Where,
C = 18.84
π = 3.14
r= ?
The missing variable is r
C = 2πr
Making r the subject
r = C / 2π
= 18.84 / 2*3,14
= 18.84 / 6.28
= 3
r = 3
The missing variable r = 3
Check:
C = 2πr
18.84 = 2*3.14*3
18.84 = 18.84