$A$ copper sphere of diameter $18\, cm$ is drawn into a wire of diameter $40\, mm$. Then,the length of the wire is......$cm$?

Find the perimeter (in $cm$) of a semicircle of radius $28\, cm$.

In a triangle $ABC$,$AB + BC = 12 \text{ cm}$,$BC + CA = 14 \text{ cm}$,and $CA + AB = 18 \text{ cm}$. Find the radius of the circle (in $\text{cm}$) which has the same perimeter as the triangle.

$ABCD$ is a trapezium with $AD$ and $BC$ as parallel sides. $E$ is a point on $BC$. The ratio of the area of $ABCD$ to that of $\Delta AED$ is

Length of a rectangle is twice of its breadth. Area of the rectangle is $18 \, m^2$. What would be its perimeter? (in $m$)

$A$ 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 $minutes$)