Question

What's the circumference of acircle with a diameter of 9 inches?Use 3.14 for T.C = [?] inches

Answer 1

Given a cricle with radius "r", the diameter "d" is related by:

`\begin{gathered} d=2r \\ r=(d)/(2) \end{gathered}`

For this circle, the circumference can be calculated by:

`c=2\pi r`

We have d = 9 in and π = 3.14. So:

`r=(9)/(2)=4.5`
`c=2\pi r=2\cdot3.14\cdot4.5=28.26`

So, the circumference is 28.26 in.