Question

The radius and slant height of Cone is 2 cm and 6cm respectively its curved surface

area is ……….........cm²​

Answer 1

$\sf Given \begin{cases} & \sf{Radius\:of\:cone = \bf{2\;cm}} \\ & \sf{Slant\:height\:of\:cone = \bf{6\:cm}} \end{cases}$

To find: Curved Surface Area of cone?

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$\dag\;{\underline{\frak{As\;we\;know\;that,}}}$

$\star\;{\boxed{\sf{\pink{Curved\:surface\:area_{\;(cone)} = \pi rl}}}}$

where,

r = radius = 2 cm

l = Slant height = 6 cm

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$\dag\;{\underline{\frak{Putting\:values\:in\:formula,}}}$

$:\implies\sf CSA_{\;(cone)} = \pi \times 2 \times 6$

$:\implies\sf CSA_{\;(cone)} = \pi \times 12$

$:\implies{\underline{\boxed{\frak{\purple{CSA_{\;(cone)} = 12 \pi cm^2 }}}}}\;\bigstar$

$\therefore\:{\underline{\sf{Curved\:surface\: area\:of\:cone\:is\: \bf{12 \pi\:or\: 37.714\:cm^2}.}}}$

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$\qquad\qquad\boxed{\bf{\mid{\overline{\underline{\pink{\bigstar\: Formulae\:related\:to\:cone :}}}}}\mid}$

$\sf Area\:of\:base = \bf{\pi r^2}$

$\sf Curved\:surface\:area\:of\:cone = \bf{\pi rl}$

$\sf Total\:surface\:area\:of\:cone = Area\:of\:base + CSA = \pi r^2 + \pi rl = \bf{\pi r(r + l)}$

$\sf Volume\:of\:cone = \bf{\dfrac{1}{3} \pi r^2 h}$