Answer:
21π m, or ≈ 65.94 m
Step-by-step explanation:
Remember that π is the ratio between a circle's circumference and its diameter, or, in equation form:
[tex]\pi=\frac{c}{d}[/tex]
where c is the circumference and d is the diameter. If we want to find the circumference, we can just multiply that equation by d on both sides to get
[tex]c=\pi d[/tex]
Here, our d = 21 m, so our circumference would be
[tex]c=21\pi[/tex] m, or approximately 21(3.14) = 65.94 m