Find the curved surface area and the total surface area of a hemisphere with a diameter of $14 \, cm$.

The length,breadth,and height of a cuboidal box are $30 \, cm$,$20 \, cm$,and $8 \, cm$ respectively. Find the lateral surface area of the cuboidal box (in $cm^2$).

Surface area of a sphere $= \ldots \ldots.$

$A$ conical tent with radius $7\, m$ and slant height $12\, m$ is to be made. How many metres of $2\, m$ wide tarpaulin will be required? If the price of tarpaulin is ₹ $48$ per meter,find the cost of the tarpaulin.

In $\Delta ABC$,$\angle B = 90^{\circ}$,$AB = 6.3 \, cm$,and $BC = 8.4 \, cm$. If the triangle is revolved about the side $AB$,find the volume of the cone so obtained. Similarly,if the triangle $ABC$ is revolved about the side $BC$,find the volume of the cone so obtained.

The radius and height of a cylinder are $10\,cm$ and $30\,cm$ respectively. Find the cost of painting its outer curved surface at the rate of ₹ $3$ per $cm^2$. (Use $\pi = 3.14$)