The ratio of the parallel sides of a trapezium is $5 : 3$. The distance between the parallel sides is $8 \mathrm{cm}$. If the area is $128 {\mathrm{cm}}^2$. find the length of the parallel sides.

In a rectangle shaped paper of length $28 \mathrm{cm}$, two equal semi-circles are drawn on one length, touching the other sides. Find the area of the shaded part in ${\mathrm{cm}}^2$(Write answer without unit).

$\left[\mathrm{Take} \mathrm{\pi }=\frac{22}{7}\right]$

 

 A wire was bent into the form of a circle of radius $7 \mathrm{cm}$. The wire is straightened and bent into the form of a square. Find the area enclosed by the square in ${\mathrm{cm}}^2$.(Write answer without unit).

$\left[\mathrm{Take} \mathrm{\pi }=\frac{22}{7}\right]$