$CSA$ of a hemisphere with diameter $20 \, cm$ is $\ldots \ldots \ldots cm^{2}$. (in $\pi$)

The dome of a temple is in the shape of a cone with radius $3.5\, m$ and height $12\, m$. Find the cost of painting its outer surface at the rate of ₹ $30/m^2$.

Write 'True' or 'False' and justify your answer:
Two identical solid hemispheres of equal base radius $r \text{ cm}$ are joined together along their bases. The total surface area of the resulting solid is $6 \pi r^{2}$.

$A$ surahi is the combination of

For a given frustum of a cone,the circumference of the base is $48 \, cm$ and the circumference of the top is $36 \, cm$. If its height is $11 \, cm$,find its volume (in $cm^3$).

The surface area of a sphere with radius $7\,cm$ is $\ldots \ldots \ldots \ldots cm ^{2}$.