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Area, SM-Bank 125

Calculate the area of the shaded region in the following composite shape, giving your answer correct to one decimal place.   (2 marks)
 

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\(22.0\ \text{m}^2\ (1 \text{ d.p.})\)

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\(\text{Radius small cirle}(r)=3\ \text{m}\)

\(\text{Radius large cirle}(R)=4\ \text{m}\)

\(\text{Total area}=\text{Area large cirle}-\text{Area small cirle}\)

\(A\) \(=\pi R^2-\pi r^2\)
  \(=\pi\times 4^2-\pi\times 3^2\)
  \(=50.265\dots-28.274\dots\)
  \(=21.991\dots\approx 22.0\ \text{m}^2\ (1 \text{ d.p.})\)