waecmaths question:
What is the total surface area of a closed cylinder of height 10cm and diameter 7cm (Take $\pi =\tfrac{22}{7}$)
Option A:
77cm2
Option B:
227cm2
Option C:
297cm2
Option D:
374cm2
waecmaths solution:
$\begin{align} & A=2\pi r(r+h) \\ & A=2\times \frac{22}{7}\times \frac{7}{2}\left( \frac{7}{2}+10 \right)c{{m}^{2}}=22\left( \frac{27}{2} \right)c{{m}^{2}}=297c{{m}^{2}} \\\end{align}$
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