Question

An exhaust fan has four blades of same size with radius of each blade 20cm , find the area of each blade if they are equally spaced . (?=3.14)

Answer 1

Dear student
$$\begin{gathered} Eachangle=\frac{360°}{8}=45° \\ Soareaof4blades\left(sector\right)=4\times \frac{\theta }{360°}\times {\mathrm{\pi r}}^2\mathrm{where}\mathrm{r}=20\mathrm{cm} \\ =4\times \frac{45°}{360°}\times 3.14\times 20\times 20 \\ =628{\mathrm{cm}}^2 \end{gathered}$$
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