The total surface area of a cone whose radius is $\frac{r}{2}$ and slant height is $2l$ is

$A$ metal pipe is $77 \,cm$ long. The inner diameter of a cross section is $4 \,cm$ and the outer diameter is $4.4 \,cm$. Find its outer curved surface area. (in $,cm^{2}$)

In $\triangle ABC$,$\angle B = 90^{\circ}$,$AB = 28 \, cm$,and $BC = 21 \, cm$. If the triangle is revolved about the side $AB$,find the curved surface area of the cone so obtained. Similarly,if the triangle $ABC$ is revolved about the side $BC$,find the curved surface area of the cone so obtained.

The radius and the slant height of a cone are in the ratio $4: 7$. The ratio of its total surface area to its curved surface area is $\ldots \ldots \ldots$

$A$ conical tent is $10 \, m$ high and the radius of its base is $24 \, m$. Find the slant height of the tent. (in $, m$)

The radius and slant height of a cone are in the ratio of $2:7$. If its curved surface area is $704 \, cm^2$,find its radius $(r)$,slant height $(l)$,and height $(h)$.