The area of the square inscribed in a circle of radius $8\, cm$ is......$cm^2$

The perimeters of a circle,a square,and an equilateral triangle are the same,and their areas are $C$,$S$,and $T$ respectively. Which of the following statements is true?

The volume of two hemispheres is in the ratio $8:27$. What is the ratio of their radii?

There are two squares $s_{1}$ and $s_{2}$. The ratio of their areas is $4:25$. If the side of $s_{1}$ is $6 \text{ cm}$,what is the side of $s_{2}$? (in $\text{cm}$)

The two adjacent sides of a parallelogram are $60 \, m$ and $40 \, m$ and one of the diagonals is $80 \, m$ long. The area of the parallelogram is

The length of a rectangular hall is $5\, m$ more than its breadth. The area of the hall is $750\, m^{2}$. The length of the hall is.........$m$