The inner and outer circumference of a circular racing track are $264 \mathrm{cm}$ and $352 \mathrm{cm}$, respectively. If the width of the racing track is $k \mathrm{cm}$, then find the value of $k$.

A wire is in the shape of a square with side $22 \mathrm{cm}$. It is bent to form a circle. If the area of the circle is $\mathrm{k} {\mathrm{cm}}^2$, the find $\mathrm{k}$.

A cardboard is in the shape of a square of side $28 \mathrm{cm}$. A circle with the biggest diameter is cut out from the square. If the remaining portion of the cardboard is $x {\mathrm{cm}}^2$, then find the value of $x$.

A cow is tied with a rope in the centre of a circular lawn of diameter $28\mathrm{cm}$. If the length of the rope is $7\mathrm{cm}$, find the area of the lawn which the cow can graze. Also find the remaining area of the lawn.

A $44\mathrm{cm}$ long wire is bent to form a square. If the same wire is bent to make a circular ring, which shape would have more area and by how much?

Find the area of the shaded region:

If the area of the region inside the rectangle excluding the triangular region is $k {\mathrm{cm}}^2$, find $k$.

Find the area of the shaded region:

_____ is the distance around a closed figure.