Grantlybrook
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# cylinder has radius 2.5 cm and lateral area 20π cm2.20π cm2. 20 pi . cm squared , . What is the surface area of the cylinder in terms of π?

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jeanette54

$\bf \textit{lateral area of a cylinder}\\\\ LA=2\pi rh\qquad \begin{cases} r=radius\\ h=height\\ -----\\ LA=20\pi \\ r=2.5 \end{cases}\implies 20\pi =2\pi \cdot 2.5h \\\\\\ \cfrac{20\pi }{2\cdot 2.5\pi }=h\implies \boxed{4=h}\\\\ -------------------------------\\\\ \textit{total surface area of a cylinder}\\\\ SA=2\pi r(h+r)\implies SA=2\pi \cdot 2.5(4+2.5)$

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