$A$ man runs around a circle of $50\, m$ radius at a speed of $12\, km/h$. Find the time taken by him for going around it ten times (in $minutes$).

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?

If a wire is bent into the shape of a square,then the area of the square is $81 \, cm^2$. When the wire is bent into a semi-circular shape,the area of the semi-circle will be (in $cm^2$):

The area of the incircle of an equilateral triangle of side $42 \ cm$ is (in $cm^2$)

The perimeter of a triangle is $30 \text{ cm}$ and its area is $30 \text{ cm}^2$. If the largest side measures $13 \text{ cm}$,then what is the length of the smallest side of the triangle? (in $\text{cm}$)

For a triangle whose sides are $50\, m$,$78\, m$,and $112\, m$ respectively,the length of the perpendicular from the opposite angle to the side $112\, m$ is ......... $m$.