Question

A cone has a circular base of radius 6mm. Given that the curved surface area of the cone is 84π mm², find its slant height.​

Answer 1

pirl=84pimm2

rl=84mm2

l=84mm2/6mm

l=14mm

Answer 2

Given :

• Radius of Cone = 6mm
• C.S.A of Cone = 84π

To Find :

• Slant Height of Cone.

Solution :

$\longmapsto\tt{Radius=6mm}$

Using Formula :

$\longmapsto\tt\boxed{C.S.A\:of\:Cone=\pi{rl}}$

Putting Values :

$\longmapsto\tt{84{\cancel{\pi}}={\cancel{\pi}}{\times{6}\times{l}}}$

$\longmapsto\tt{84=6\times{l}}$

$\longmapsto\tt{84=6l}$

$\longmapsto\tt{l=\cancel\dfrac{84}{6}}$

$\longmapsto\tt\bf{l=14mm}$

So , The Slant Height of Cone is 14mm...

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• C.S.A of Cone = πrl
• T.S.A of Cone = πrl(l+r)
• Volume of Cone = 1/3 πr²h
• Slant Height of Cone = √(r)²+(h)²

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