Calculate the perimeter of a regular hexagon with vertices on a circle of diameter $1$ centimetre. Write the answer in centimetre.

In the picture below, a regular hexagon is drawn with its vertices on a circle. Calculate the perimeter of the circle in $\mathrm{cm}$. Take $\mathrm{\pi }=3.14$.

In the picture below, a square is drawn with its vertices on a circle. Calculate the perimeter of the circle.

In the picture below, a rectangle is drawn with its vertices on a circle. If the perimeter of the circle is $k \mathrm{cm}$ (in decimal) then find $k$. Take $\mathrm{\pi }=3.14$