Explanation
From the question we can see that the radii of the circles is given as
[tex]\begin{gathered} r_{big}=11metres \\ r_{small}=9metres \end{gathered}[/tex]
Therefore, we will then find the area of the big circle and the small circle.
[tex]\begin{gathered} Area_{big}=\pi r_{big}^2=3.14\times11^2=379.94m^2 \\ Area_{small}=\pi r_{small}^2=3.14\times9^2=254.34m^2 \end{gathered}[/tex]
Therefore, the area of the sidewalk is the difference between the area of the big circle and the area of the small circle.
[tex]Area\text{ of side walk = }Area_{big}-Area_{small}=379.94-254.34=125.6m^2[/tex]
Answer: 125.6 square meteres
