Question

Find the radius when arc length is 18pi/7 and 0=6pi/7

Answer 1

r = 3

Explanation:

the arc length is calculated as

arc = circumference of circle × fraction of circle , then

`(18\pi )/(7)` = 2πr ×
`(0)/(2\pi )` ( cancel 2π on numerator/ denominator )

`(18\pi )/(7)` = r ×
`(6\pi )/(7)` ( multiply both sides by 7 to clear the fractions )

18π = r × 6π ( divide both sides by 6π )

3 = r