is the distance around a closed figure.

If the area of a circular ring with outer and inner radii as $\mathrm{R}$ and $\mathrm{r}$, respectively is $\mathrm{\pi k}(\mathrm{R}+\mathrm{r})$, then find $\mathrm{k}$.

A square and a parallelogram have equal areas. If the side of the square is $30 \mathrm{m}$ and the height of the parallelogram is $15 \mathrm{m}$, find the length of the parallelogram.

If the area of a square inscribed in a circle of radius $3.5 \mathrm{cm}$ if $k {\mathrm{cm}}^2$, find $k$ in decimal.

The area of a triangle is equal to the area of a square of side $30 \mathrm{cm}$. Its altitude is $90 \mathrm{cm}$. If the length of the base of the triangle is $k \mathrm{cm}$, find $k$.

If the area of the unshaded portion in the figure given alongside is $\mathrm{k} {\mathrm{mm}}^2$, then find $\mathrm{k}$.

Find the area and circumference of a circle of radius $21$ $\mathrm{cm}$. [Take $\mathrm{\pi }=\frac{22}{7}$]

The dimensions of a photo are $60 \mathrm{cm}$ by $38 \mathrm{cm}$. Sunil wants to frame the photo. The layout of the frame with photo is shown here. If the area of the frame is $k {\mathrm{cm}}^2$, find $k$.

The area of the shaded portion is $k {\mathrm{cm}}^2$. Find $k$.