Find the area of the sector of a circle of radius $5\, cm$,if the corresponding arc length is $3.5\, cm$. (in $cm^2$)

While calculating the area of a circle,its radius was taken to be $6 \, cm$ instead of $5 \, cm$. The calculated area is $\dots \%$ more than the actual area.

Sides of a triangular field are $15 \, m$,$16 \, m$,and $17 \, m$. At the three corners of the field,a cow,a buffalo,and a horse are tied separately with ropes of length $7 \, m$ each to graze in the field. Find the area of the field which cannot be grazed by the three animals.

The wheel of a motorcycle has a radius of $35 \, cm$. How many revolutions per minute must the wheel make to maintain a speed of $66 \, km/h$?

The circumference of a circular ground is $352\, m$. Find the area of the ground (in $m^2$).

The circumference of a circle is $176 \, cm$. Find its radius in $cm$.