Question

What is LSA of frustum of Cone? Is the given formula right?

Answer 1

π×length(radius of bigger cone+radius of smaller cone)

Answer 2

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$\bf\Huge\red{\mid{\overline{\underline{ ANSWER }}}\mid }$

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$\Large\fbox{\color{purple}{QUESTION}}$

SURFACE AREA VOLUME FORMULAS

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$\Large\fbox{\color{purple}{ SOLUTION }}$

$\Large\mathcal\green{FRUSTUM}$

$\implies \: lsa = \pi \: l(r1 + r2)$

$\implies volume = \frac{1}{3}\pi \: h( {r1}^{2} + r1.r2 + {r2}^{2} )$

$\Large\mathcal\purple{CUBOID}$

$\implies \: lsa = 2(l + b)h \\ \\ \: \implies \: tsa = 2(lb + bl + hl) \\ \\ \implies \: volume \: = l \times b \times h$

$\Large\mathcal\blue{CUBE}$

$\implies \: lsa = {4a}^{2} \\ \\ \implies \: tsa = {6a}^{2} \\ \\ \implies \: volume = {a}^{3}$

$\Large\mathcal\brown{CYLINDER}$

$\implies \: csa = 2\pi \: r \: h \\ \\ \implies \: tsa = 2\pi \: r(r + h) \\ \\ \implies \: volume \: = \pi \: {r}^{2} h</p><p>$

$\Large\mathcal\orange{CONE}$

$\implies \: tsa \: = \: \pi \: r \: (l + r) \\ \\ \implies \: csa \: = \pi \: r \: l\\ \\ \implies \: volume \: = \frac{1}{3} (\pi \: {r}^{2} h)$

$\Large\mathcal\red {SPHERE }$

$\implies \: tsa \: = 4\pi \: {r}^{2} \\ \\ \implies \: csa \: = 4\pi \: {r}^{2} \\ \\ \implies \: volume \: = \frac{4}{3} \: {r}^{3}$

$\Large\mathcal\pink{HEMISPHERE}$

$\implies \: tsa \: =3\pi \: {r}^{2} \\ \\ \implies \: csa \: = 2\pi \: {r}^{2} \\ \\ \implies \: volume \: = \frac{2}{3} \pi \: {r}^{3}$

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$\bf\Large\red{ THANKS \: FOR \: YOUR}$

$\bf\Large\red{ QUESTION \: HOPE \: IT }$

$\bf\Large\red{ HELPS }$

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