Find the area of a rhombus whose perimeter is $4a$ and the length of one of the diagonals is $x$.

The diameter of a coin is$1 \mathrm{cm}$. If four of these coins  be placed on a table so that the rim of each touches that of the other two, find the area of the unoccupied space between them.

The length and breadth of the floor of a hall is $20 \mathrm{m}$ and $10 \mathrm{m}$ respectively. Squares tiles of $2 \mathrm{m}$ dimensions in three different colours are placed on the floor. The first row of tiles on all sides is black. Out of the remaining, one-third are white and the rest are blue. How many blue tiles are there?

An ant is moving around a few food pieces of different shapes scattered on the floor. Remember, circumference of a circle can be obtained by using the expression $c=2\mathrm{\pi r}$, where $r$ is the radius of the circle.

An ant is moving around a few food pieces of different shapes scattered on the floor. Remember, circumference of a circle can be obtained by using the expression $c=2\mathrm{\pi r}$, where $r$ is the radius of the circle.

An ant is moving around a few food pieces of different shapes scattered on the floor. Remember, circumferernce of a circle can be obtained by using expression $c=2\mathrm{\pi r}$, where $r$ is the radius of the circle.

The shape of the top surface of a table is a trapezium. Find its area of if its parallel sides are $1 \mathrm{m}$ and $1.2 \mathrm{m}$ and perpendicular distance between them is $0.8 \mathrm{m}$