The sides of a triangle are in the ratio $3:4:5$. If its perimeter is $36 \text{ cm}$,then the area of the triangle is ...... $\text{cm}^2$.

Wheels of diameters $7\, cm$ and $14\, cm$ start rolling simultaneously from $X$ and $Y$,which are $1980\, cm$ apart,towards each other in opposite directions. Both of them make the same number of revolutions per second. If both of them meet after $10\, seconds$,the speed of the smaller wheel is.........$cm/sec$.

If a diagonal of a square is doubled,how does the area of the square change?

The area of a big rectangle is equal to the area of a small rectangle. If the length of the big rectangle is equal to the length of the small rectangle and the width of the big rectangle is $2 \ m$,what is the width of the small rectangle?

The length of a rectangular plot is $20 \ m$ more than its breadth. If the cost of fencing the plot at $₹ 26.50/m$ is $₹ 5300$,what is the length of the plot in metres?

In the figure,$DE \parallel BC$. If $DE = 3 \text{ cm}$,$BC = 6 \text{ cm}$,and the area of $\Delta ADE = 15 \text{ cm}^2$,then the area of $\Delta ABC$ is ............ $\text{cm}^2$.