The curved surface area of a cylinder is $132 \, cm^2$. If its height is $3 \, cm$,its diameter is $\dots \dots \dots \, cm$.

Two identical cubes each of volume $64 \, cm^{3}$ are joined together end to end. What is the surface area of the resulting cuboid? (in $cm^{2}$)

Curved surface area of a hemisphere $= \ldots \ldots \ldots . .$

Write 'True' or 'False' and justify your answer:
$A$ solid cone of radius $r$ and height $h$ is placed over a solid cylinder having the same base radius and height as that of the cone. The total surface area of the combined solid is $\pi[\sqrt{r^{2}+h^{2}}+3r+2h]$.

The ratio of radii of two spheres is $3:2$. Then,the ratio of their surface areas is $\ldots \ldots \ldots \ldots$

$A$ cylinder is closed at both the ends by hemispheres. The radius of the cylinder is $20 \, cm$ and the total height of the article is $80 \, cm$. Find the total surface area of this combined article. $(\pi = 3.14)$ (in $cm^2$)