If the radius of one circle is $12$ times the radius of another,how many times does the area of the greater circle contain the area of the smaller circle?

Find the area of a rhombus one of whose diagonals measures $10 \text{ cm}$ and the other $12 \text{ cm}$. (in $\text{cm}^2$)

$A$ hollow spherical shell is made of a metal of density $4.9 \, g/cm^3$. If its internal and external radii are $10 \, cm$ and $12 \, cm$ respectively,find the weight of the shell. (Take $\pi = 3.1416$) (in $gm$)

If all the sides of a triangle are increased by $200 \%$,then the area of the triangle will increase by (in $\%$):

If the length of one diagonal of a rhombus is $80 \%$ of the length of the other diagonal,the area of the rhombus is how many times the square of the length of the longer diagonal?

$A$ piece of wire $132 \, cm$ long is bent successively in the shapes of an equilateral triangle,a square,a regular hexagon,and a circle. Then,which has the largest surface area?