Silo

The outer perimeter of the silo is 32 m. The concrete wall is 35 cm thick. What is the diameter and area of the inside floor of the silo?

Correct answer:

d =  9.49 m
S =  70.67 m²

Step-by-step explanation:

$$\begin{gathered} 32=2\pi r=\pi D \\ d=D-2h=\frac{32}{\pi }-\frac{2\cdot 35}{100}=9.49\text{m} \end{gathered}$$

$S=\pi r^2=\pi \frac{d^2}{4}=70.67{\text{m}}^2$

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