Question

The height of a cone is 15cm.if it's volume is 1570cu.cm,find its radius

Answer 1

Given :

• Height of Cone = 15cm
• Volume of Cone = 1570cm³

To Find :

• Radius of the base of cone.

Solution :

$\longmapsto\tt{Height=15cm}$

Using Formula :

$\longmapsto\tt\boxed{Volume\:of\:Cone=\dfrac{1}{3}\pi{{r}^{2}h}}$

Putting Values :

$\longmapsto\tt{1570=\dfrac{1}{\cancel{3}}\times{3.1r}\times{{r}^{2}}\times{\cancel{15}}}$

$\longmapsto\tt{1570=3.14\times{{r}^{2}}\times{5}}$

$\longmapsto\tt{1570=15.7\times{{r}^{2}}}$

$\longmapsto\tt{{r}^{2}=\cancel\dfrac{15700}{157}}$

$\longmapsto\tt{r=\sqrt{100}}$

$\longmapsto\tt\bold{r=10cm}$

So , The radius of the cone is 10cm...

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• C.S.A of Cone = πrl
• T.S.A of Cone = πr(l+r)
• Volume of Cone = 1/3πr²h

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