Respuesta :
Answer: The answer is 314.28 cm² (approx.).
Step-by-step explanation: Given that an engineer is going to install a new water pipe. The diameter of this circular pipe is, d = 20 cm.
We need to find the area 'A' of the circular cross-section of the pipe.
Given, diameter of the circular section is
[tex]\textup{d}=20~\textup{cm}.[/tex]
So, the radius of the circular cross-section will be
[tex]\textup{r}=\dfrac{\textup{d}}{2}=\dfrac{20}{2}=10~\textup{cm}.[/tex]
Therefore, cross-sectional area of the pipe is
[tex]\textup{A}=\pi \textup{r}^2=\dfrac{22}{7}(10)^2=\dfrac{2200}{7}=314\dfrac{2}{7}=314.28~.~.~.~\textup{cm}^2.[/tex]
Thus, the answer is 314.28 cm² (approx.).
