The length of a rectangle is increased by $33.33 \%$. By what percent should the width be decreased to maintain the same area? (in $\%$)

The radius of the wheel of a vehicle is $70\, cm$. The wheel makes $10$ revolutions in $5\, seconds$. The speed of the vehicle is......$km/h$.

The area of the circumcircle of an equilateral triangle is $3 \pi \, cm^2$. The perimeter of the triangle is

$3$ horses are tethered at $3$ corners of a triangular plot of land having sides $20 \, m$,$30 \, m$,and $40 \, m$,each with a rope of length $7 \, m$. The area (in $m^2$) of the region of this plot,which can be grazed by the horses,is (Use $\pi = \frac{22}{7}$)

The area of a sector of a circle of radius $5 \, cm$,formed by an arc of length $3.5 \, cm$,is (in $cm^2$)

Each side of an equilateral triangle is increased by $1.5 \%$. The percentage increase in its area is......$\%$