Sidewalk

The city park is a circular bed of flowers with a diameter of 8 meters. Around it, the whole length is 1-meter wide sidewalk. What is the sidewalk area?

Correct answer:

S =  28.27 m²

Step-by-step explanation:

$$\begin{gathered} D=8\text{m} \\ r=D/2=8/2=4\text{m} \\ s=1\text{m} \\ {S}_1=\pi \cdot r^2=3.1416\cdot 4^2\doteq 50.2655{\text{m}}^2 \\ {S}_2=\pi \cdot (r+s{)}^2=3.1416\cdot (4+1{)}^2\doteq 78.5398{\text{m}}^2 \\ S=S_2-S_1=78.5398-50.2655=28.27{\text{m}}^2 \end{gathered}$$

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