need some help with question 20

Answer:
l = 420 cm
Step-by-step explanation:
20.
Central angle = 60°
The radius of circle, r = 7 cm
We need to find the length of the arc. We can find it as follows :
[tex]l=r\times \theta\\\\l=7\times 60\\\\l=420\ cm[/tex]
So, the length of the arc is equal to 420 cm.