The diameter of the moon is approximately one-fourth of the diameter of the earth. Find the ratio of their surface areas.

Find the capacity in litres of a conical vessel with height $12 \,cm$ and slant height $13 \,cm$.

In a hot water heating system,there is a cylindrical pipe of length $28 \, m$ and diameter $5 \, cm$. Find the total radiating surface in the system. $\left[ \text{Assume } \pi = \frac{22}{7} \right]$ (in $, m^2$)

Diameter of the base of a cone is $10.5\, cm$ and its slant height is $10\, cm$. Find its curved surface area. Assume $\pi = \frac{22}{7}$. (in $, cm^2$)

$A$ small indoor greenhouse (herbarium) is made entirely of glass panes (including base) held together with tape. It is $30 \, cm$ long,$25 \, cm$ wide and $25 \, cm$ high. What is the area of the glass (in $, cm^2$)?

$A$ child is playing with building blocks, which are in the shape of cubes, and has built a structure as shown in the figure. If the edge of each cube is $3 \, cm$, find the volume of the structure built by the child. (in $cm^3$)