Show that the right-circular cone of least curved surface and given volume has an altitude equal to `sqrt(2)` times the radius of the base.

Explanation

Let `r,l "and" h` be the radius, slant height and altitude of the cone respectively, then


`v=1/3(pir^2h)`........(1)


`h=(3v)/(pir^2)`.......(2)


`s=pirl`, squaring both sides


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