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42 votes
42 votes
A cone with a height of 4 in, and a diameter of 6 in. Find the surface area and Volume​

User Gopesh
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1 Answer

25 votes
25 votes

if its diameter is 6, then its radius is half that or 3.


\textit{volume of a cone}\\\\ V=\cfrac{\pi r^2 h }{3}~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ r=3\\ h=4 \end{cases}\implies V=\cfrac{\pi (3)^2(4)}{3}\implies V=12\pi \\\\[-0.35em] ~\dotfill\\\\ \textit{surface area of a cone}\\\\ SA=\pi r√(r^2+h^2)+\pi r^2\qquad \implies \qquad SA=\pi (3)√(3^2+4^2)+\pi (3)^2 \\\\\\ 3\pi √(25)+9\pi \implies 3\pi (5)+9\pi \implies 15\pi +9\pi \implies 24\pi

User Frangio
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