The circumference (perimeter) of a circle is given as:
![C=\pi D](https://img.qammunity.org/2023/formulas/mathematics/college/pjgw9lxpy7n1s9o3u37yvd47u2h34s8hvv.png)
Plugging the value given we have that:
![\begin{gathered} 21.99=3.14D \\ D=(21.99)/(3.14) \\ D=7.003 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/36n39gyf6lxa60pgn0c4qh8hevqa4l8qx7.png)
Rounding the diameter we have that it is 7 meter. The radius is half the diameter, then the radius is 3.5.
Therefore the diameter is 7 meters and the radius is 3.5 meters.