If the circumference and the area of a circle are numerically equal,then the diameter is equal to

$A$ man runs round a circular field of radius $50\, m$ at the speed of $12\, km/hr$. What is the time taken by the man to take twenty rounds of the field? (in $minutes$)

If the perimeter of a semi-circular protractor is $36 \, cm$,then its diameter is ...... $cm$?

The circumference of a circle is $176\, m$. Then,its area is

The largest cone is formed at the base of a cube of side measuring $7 \ cm$. Find the ratio of the volume of the cone to the volume of the cube.

$A$ rectangular park $60 \, m$ long and $40 \, m$ wide has two concrete crossroads running in the middle of the park, and the rest of the park has been used as a lawn. If the area of the lawn is $2109 \, m^2$, then what is the width of the road? (in $m$)