Lake path calculation

Lake Trasimeno is approximately in the shape of a circle, its area is about 28 square kilometers, and Mr. Hector's walking speed is approximately 4 km/h. Calculate the length of the path around the lake and how many hours Mr. Hector would have to walk to overcome (circumvent) the lake.

Final Answer:

o =  18.7579 km
t =  4.6895 h

Step-by-step explanation:

$$\begin{gathered} S=28{\text{km}}^2 \\ S=\pi r^2 \\ r=\sqrt{S/\pi }=\sqrt{28/3.1416}\doteq 2.9854\text{km} \\ o=2\pi \cdot r=2\cdot 3.1416\cdot 2.9854=18.7579\text{km} \end{gathered}$$

$$\begin{gathered} v=4\text{km/h} \\ o=vt \\ t=o/v=18.7579/4=4.6895\text{h} \end{gathered}$$

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